[Senate Hearing 118-545]
[From the U.S. Government Publishing Office]


                                                       S. Hrg. 118-545

                     AI IN CRIMINAL INVESTIGATIONS
                            AND PROSECUTIONS

=======================================================================

                                HEARING

                               BEFORE THE

                     SUBCOMMITTEE ON CRIMINAL JUSTICE 
                             AND COUNTERTERRORISM

                                 OF THE

                       COMMITTEE ON THE JUDICIARY
                          UNITED STATES SENATE

                    ONE HUNDRED EIGHTEENTH CONGRESS

                             SECOND SESSION

                               __________

                            JANUARY 24, 2024

                               __________

                           Serial No. J-118-52

                               __________

         Printed for the use of the Committee on the Judiciary
         
[GRAPHIC NOT AVAILABLE IN TIFF FORMAT]         


                        www.judiciary.senate.gov
                            www.govinfo.gov
                            
                                __________

                   U.S. GOVERNMENT PUBLISHING OFFICE                    
58-370                     WASHINGTON : 2025                  
          
-----------------------------------------------------------------------------------     
                           
                       COMMITTEE ON THE JUDICIARY

                   RICHARD J. DURBIN, Illinois, Chair
SHELDON WHITEHOUSE, Rhode Island     LINDSEY O. GRAHAM, South Carolina, 
AMY KLOBUCHAR, Minnesota                 Ranking Member
CHRISTOPHER A. COONS, Delaware       CHARLES E. GRASSLEY, Iowa
RICHARD BLUMENTHAL, Connecticut      JOHN CORNYN, Texas
MAZIE K. HIRONO, Hawaii              MICHAEL S. LEE, Utah
CORY A. BOOKER, New Jersey           TED CRUZ, Texas
ALEX PADILLA, California             JOSH HAWLEY, Missouri
JON OSSOFF, Georgia                  TOM COTTON, Arkansas
PETER WELCH, Vermont                 JOHN KENNEDY, Louisiana
LAPHONZA BUTLER, California          THOM TILLIS, North Carolina
                                     MARSHA BLACKBURN, Tennessee
                 Joseph Zogby, Majority Staff Director
                Katherine Nikas, Minority Staff Director

         Subcommittee on Criminal Justice and Counterterrorism

                   CORY A. BOOKER, New Jersey, Chair
SHELDON WHITEHOUSE, Rhode Island     TOM COTTON, Arkansas, Ranking 
AMY KLOBUCHAR, Minnesota                 Member
CHRISTOPHER A. COONS, Delaware       CHARLES E. GRASSLEY, Iowa
PADILLA, ALEX, California            JOHN CORNYN, Texas
OSSOFF, JON, Georgia                 MICHAEL S. LEE, Utah
LAPHONZA BUTLER, California          TED CRUZ, Texas
                                     JOHN KENNEDY, Louisiana
                 Lynda Garcia, Democratic Chief Counsel
                 Drew Hudson, Republican Chief Counsel
                            
                            
                            C O N T E N T S

                              ----------                              

                           OPENING STATEMENTS

                                                                   Page

Booker, Hon. Cory A..............................................     1
    Prepared statement...........................................    32
Cotton, Hon. Tom.................................................     2

                               WITNESSES

Aguilar, Armando.................................................     5
    Prepared statement...........................................    35
    Responses to written questions...............................    61
Howard, Karen L..................................................     7
    Prepared statement...........................................    38
    Responses to written questions...............................    63
Wexler, Rebecca..................................................     9
    Prepared statement...........................................    54
    Questions submitted with no response returned................    64

                                APPENDIX

Items submitted for the record...................................    31

 
                     AI IN CRIMINAL INVESTIGATIONS
                            AND PROSECUTIONS

                              ----------                              


                      WEDNESDAY, JANUARY 24, 2024

                      United States Senate,
              Subcommittee on Criminal Justice and 
                                  Counterterrorism,
                                Committee on the Judiciary,
                                                    Washington, DC.
    The Subcommittee met, pursuant to notice, at 2:32 p.m., in 
Room 226, Dirksen Senate Office Building, Hon. Cory A. Booker, 
Chair of the Subcommittee, presiding.
    Present: Senators Booker [presiding], Whitehouse, Padilla, 
Ossoff, Butler, Cotton, and Kennedy.

           OPENING STATEMENT OF HON. CORY A. BOOKER, 
          A U.S. SENATOR FROM THE STATE OF NEW JERSEY

    Chair Booker. Hello, everybody. I'm excited to see such a 
crowd, almost standing room only. There's a whole bunch of 
people waiting outside. I'm not sure if it was because of the 
rumors that broke out on Twitter that you and I were going to 
have a cage match.
    But in all seriousness, I can't tell you how excited I am 
being next to Tom Cotton for this hearing because I think as 
much as Tom Cotton and I have that differs us, we actually both 
have a lot of the same commitment to community safety. And I 
think this is a hearing that strikes right to the heart of 
keeping communities safe and strong. And I'm excited that the 
two of us are here for this inquiry, really to hear from folks 
about an issue that is really exciting.
    There is much made of technology and its influence on our 
society. When I was mayor of the city of Newark, the number one 
issue of my constituents, the pollster that I had and never 
seen anything like it, was the safety and the security of our 
neighborhoods and communities. And what was exciting for me is 
that we introduced a lot of technology as a mechanism with 
which to keep people safe, technology now that some of our 
witnesses actually can talk to, like ShotSpotters, and cameras, 
license plate readers, and more.
    And what excites me now is I was a mayor about 11 years 
ago, which is a long time when it comes to the advancements of 
technology and innovation. We know that technology in America 
has so much promise, and in this sphere, it could do a lot. 
Many people will be stunned to know that our murder clearance 
rates in the United States is--something where, Chief Aguilar, 
you can help me out--but somewhere around 50 percent.
    Mr. Aguilar. Correct.
    Chair Booker. Yeah. It's astonishingly--I think that was a 
hallelujah that he said there. Amen, Senator Booker--is 
astonishingly low. And so, one of the things that a lot of 
people don't realize is that technology could help us on 
clearance rates. It could help us to create more community 
trust. It could help us on investigations. It could help us in 
so many positive ways.
    But we also know that technology presents a lot of 
possibilities to undermine our core values and our ideals as 
well when it comes to certain constitutional protections, when 
it comes to privacy, when it comes to some of the most 
sacrosanct elements of our democracy. And so we know that AI is 
consequential in our society as a whole in ways that many of us 
can't fully imagine, both in the possibility in the promise, as 
well as the potential problems.
    When it comes to our criminal justice system, where often a 
person's liberty and a person's life are at stake, when the 
safety of their neighborhoods are at stake, where their 
constitutional protections are at stake is particularly 
consequential. Law enforcement's use of artificial intelligence 
technology is not a recent development, again, as all of our 
experts can attest to.
    Its recent expansion raises a lot of questions, as well as 
raises a lot of excitement for me about the possibilities. And 
so, I'm going to submit the rest of my opening testimony for 
the record.
    [The prepared statement of Chair Booker appears as a 
submission for the record.]
    Chair Booker. But I do want to say to the witnesses that 
are here, how excited I am. I know you all made sacrifices and 
took time out. I'm going to introduce you in a moment after my 
Ranking Member, Senator Cotton, does this opening statement.
    But we really are at a point in humanity where every 
generation has breakthrough technologies that shape and alter 
the course of humanity. AI is most certainly one of those 
things, and I know that Senator Cotton and I both are committed 
to trying to find a way to capture the possibility as well as 
protect against the risks.
    And with that I'm very excited and very grateful to Senator 
Cotton and his entire team for helping to make this hearing 
possible. And I will turn the microphone over to him for his 
opening remarks.

             OPENING STATEMENT OF HON. TOM COTTON, 
           A U.S. SENATOR FROM THE STATE OF ARKANSAS

    Senator Cotton. Thank you, Senator Booker. I would say that 
artificial intelligence has gained a lot of attention lately, 
over the last year and a half or so in particular, but the core 
technology has been around for some time because of how it's 
depicted.
    Maybe we start with what it's not. Many people, 
fortunately, most people, don't have much personal interaction 
with law enforcement or with the criminal justice system. What 
is AI in law enforcement? It's not RoboCop, it's not the 
Terminator, it's not the Matrix, not Ultron, it's not even 
WALL-E. It is never used independent of human decisionmaking in 
our criminal justice system. That's why it's a tool in the law 
enforcement toolbox, and it can provide impressive time-saving, 
and crime-solving, and justice-serving tools.
    Just one example. Facial recognition software, for 
instance, could take a crime scene sketch or a security camera 
image, and go through thousands and thousands of pictures in a 
public data base, say a driver's license data base. It can 
eliminate obvious non-matches. It might be even narrow it down, 
but then that is a tool that independent human judgment can use 
to pursue leads. If the early stages of a criminal 
investigation are like looking for a needle in a haystack, then 
artificial intelligence, if you will, can provide a magnet for 
some of our criminal investigators in the police forces around 
the country.
    That's why I want to enter into the record with consent 
here, a statement from the National Sheriff's Association, 
Major County Sheriffs of America, and the Major Cities Chief 
Association. They represent State and local law enforcement all 
across the country. I want to highlight one particular line 
from their statement. ``It is essential to recognize that AI-
powered technology serves as an investigative assistant to law 
enforcement rather than a replacement for the human element.'' 
Mr. Chairman, I ask consent to enter that statement into the 
record.
    Chair Booker. Without objection.
    Senator Cotton. I also want to give one concrete real-world 
example of how this can work. Last summer, British authorities 
contacted the Department of Homeland Security about a video, 
child sexual exploitation. They had reason to believe it was 
made in the United States. DHS ran the faces against a mass 
data base of photos, and they found a match. A college sports 
administrator in Missouri.
    Investigators then found the suspect's Facebook profile and 
were able to confirm not only that it was the same person, but 
even that the child victim was on his Facebook page. They 
eventually got a search warrant from a judge, and in July, they 
were able to arrest and charge this predator. Without that 
facial recognition technology, he might be free today, and that 
child might still be subjected to abuse today as well.
    AI-powered law enforcement tools also improve efficiency 
and save lives in other ways. For instance, by modeling where 
and when crimes happen, law enforcement agencies can better 
position limited patrol units to prevent crimes or to respond 
quickly. They can coordinate with other emergency services like 
ambulances for better staffing at times and places where there 
would be needed.
    And yet other cases, AI-powered products like those made by 
Motorola Solutions are used by 911 call centers to clean up, 
transcribe, and even translate 911 calls in real time, or an AI 
product made by the company, Axon, is used by law enforcement 
to quickly blur faces and body cam footage, so police 
departments can share the footage with the public faster. Other 
AI-powered tools can analyze financial records to help identify 
financial crime, and AI-powered cameras can recognize license 
plates of wanted individuals and alert law enforcement to 
investigate.
    Now, I understand there are some who have concerns about 
the use of artificial intelligence technology in law 
enforcement, and those concerns are in some cases valid and 
should be aired, which I think we'll do today. But I do want to 
point out that probably the most uncomfortable people with the 
use of artificial intelligence are criminals who would like to 
avoid being caught because, again, artificial intelligence is 
simply a tool that human investigators, police officers, 
prosecutors, can use to help solve cases, convict criminals, 
and put them behind bars.
    We need to remember that artificial intelligence-powered 
law enforcement tools are assistive technologies helping law 
enforcement officers be better at their jobs, and responsibly 
used, these technologies can help create a faster, cheaper, 
more accurate criminal justice system where the criminals are 
being caught, prosecuted, and victims are being provided 
justice, and the innocent are not being punished.
    I know our witnesses have thoughts and expertise to share 
on these questions, and I look forward to today's conversation. 
I do want to say and apologize in advance that since this 
hearing was scheduled, the Republican Conference has scheduled 
an all-Republican meeting about the National Security 
Supplemental Bill that is currently under debate. So, I may not 
make it to the end, but I assure you it has nothing to do with 
your testimony. Thank you-all.
    Chair Booker. Senator Cotton, thank you for those excellent 
remarks. You went through an array of movies there from WALL-E 
to Terminator. Were those recommendations, or did your staff 
sort of put them in?
    [Laughter.]
    Chair Booker. All right. I am excited that what I'm going 
to do now is introduce all the witnesses, and then I'm going to 
ask you to stand up, and raise your right hand, and swear an 
oath. We prefer you not to swear at us, but just swear the 
oath, and then we'll go and open it up for your testimony in 
alphabetical order.
    So, I'm going to introduce really quickly the Assistant 
Chief of Police, Armando Aguilar, from the city of Miami 
Department and Law Enforcement Subcommittee Member of the 
National Artificial Intelligence Advisory Committee. Assistant 
Chief Aguilar is assistant chief of police for the city of 
Miami Police Department, which is having some extraordinary 
success in protecting citizens and keeping their community 
safe.
    In 2022, you began serving as a member of the Law 
Enforcement Subcommittee of the National Artificial 
Intelligence Advisory Committee, which advises the President of 
the United States on matters related to the use of AI in law 
enforcement. As assistant chief of police, you oversee hundreds 
of sworn and civilian employees, and you've held many senior 
management positions in all divisions of the Miami Police 
Department.
    During your time with MPD, you have implemented offender-
focused strategies that have contributed to significant 
reductions in violent crime and significant increases in 
clearance rates. You hold a master in public administration 
from Barry University, and a bachelor's of criminal justice 
from Saint Leo University. It's really an honor to have you 
here, and we're very, very grateful.
    I want to next introduce Dr. Karen Howard, Ph.D. Dr. Howard 
works with the U.S. Government Accountability Office, or GAO, 
as acting chief scientist, a role that she held from Jan.-Oct. 
2023, and a director of the GAO Science, Technology Assessment, 
and Analytics Team, STAA. You manage a broad portfolio of 
topics, frankly, an impressive portfolio of topics, including 
forensic algorithms, biological threats, chemical weapons, 
national security implications of emerging technologies, and 
other issues. It's pretty extraordinary the work you do.
    You've produced key GAO reports that you're going to 
testify about, including forensic technology algorithms used in 
Federal law enforcement, and Forensic Technology: Algorithms 
Strengthen Forensic Analysis, but Several Factors Can Affect 
Outcomes. You've earned your Ph.D. in environmental chemistry 
and your master's degree in analytical chemistry. You are, as 
my dad would say, you have more degrees than the month of July, 
and it's great to have you here. And thank you for, again, 
flying up from Alabama as well.
    It's difficult for me, Professor Wexler, you have so much 
Berkeley on your resume. As a Stanford man, I'm going to try to 
muscle my way through this. Okay. You are assistant professor 
of law at the University of Berkeley School of Law and faculty 
co-director. You're the co-director for the Berkeley Center of 
Law and Technology.
    Professor Wexler is a faculty co-director of the Berkeley 
Center for Law and Technology, and assistant professor of law 
at UC, Berkeley. Your teaching and research focus on data 
technology and secrecy in the criminal legal system. Your 
scholarship has appeared in so many places; the Harvard Law 
Review, Stanford Law Review, Yale Law Journal Forum, NYU Law 
Review, UCLA Law Review, Texas Law Review, Vanderbilt Law 
Review, Berkeley Technology Law Review. I would criticize you 
because nothing in Arkansas. You need to correct for that.
    Professor Wexler served as Senior Policy Advisor for 
Science and Justice at the White House Office of Science and 
Technology during the spring of 2023, and as the James C. 
Carpenter visiting professor at Columbia Law School. You've got 
your JD from Yale, MPhil from Cambridge as a Gates Scholar, and 
you are summa cum laude at Harvard. And again, we thank you for 
flying in all the way from California. Would the three 
witnesses please stand up and raise your right hand?
    [Witnesses are sworn in.]
    Chair Booker. Let the record show that each witness has 
answered in the affirmative. You may sit down, unless you want 
to stand for the hearing, which of course we have no 
preference. You each will now have 5 minutes for your opening 
statement. And again, we're going to start with an alphabetical 
order with Chief Aguilar.

 STATEMENT OF MR. ARMANDO AGUILAR, ASSISTANT CHIEF OF POLICE, 
            MIAMI POLICE DEPARTMENT, MIAMI, FLORIDA

    Mr. Aguilar. Good afternoon, Subcommittee Chair Booker, 
Ranking Member Cotton, and Subcommittee Members. I'm Armando 
Aguilar, assistant chief of police at the Miami Police 
Department, also currently serving a 3-year term as a member of 
the Law Enforcement Subcommittee of the National Artificial 
Intelligence Advisor Committee, or NAIAC-LE. I would, however, 
like to point out that I'm speaking here today on behalf of the 
Miami Police Department and not on my position on NAIAC-LE.
    I'm proud to say that the Miami Police Department story is 
among the greatest turnaround stories in law enforcement. In 
1980, Miami with a murder rate comparable to that of Honduras, 
was America's murder capital. I became a Miami police officer 
in 2001, and a homicide detective in late 2004; a year when 69 
people would be murdered in Miami and another 6,400 would fall 
victim to violent crime.
    By this time, we had the audacity to high-five each other 
because we were no longer in the top five most violent cities 
in America. We were, however, perennially on the top 25 list. 
Fast-forward to 2023, Miami ended the year with 31 murders and 
2,600 violent crimes. Thirty one and 2,600 too many still.
    Our murder clearance rate, the rate at which cases are 
solved, was 68 percent, or 97 percent under the FBI's Legacy 
Reporting System, which counts prior year cases closed during 
2023. Our violent crime clearance rate was 58 percent. Now, for 
most of my career, our murder clearance rate hovered below 45 
percent, and our violent crime clearance rate below 38 percent. 
So, what changed? A great deal.
    I'll begin by stating that I've had the pleasure of leading 
the best generation of officers, detectives, and professional 
staff to serve the people of Miami, and our success begins with 
community trust. Violent crime, especially unsolved violent 
crime, is among the greatest threats which serve to undermine 
that trust. A shooting takes place, a community member calls in 
an anonymous tip. The police without any other leads to 
corroborate the tip, will eventually result in the case going 
cold. People stop reporting gunfire, the police in turn do not 
respond to gunfire that we don't know about.
    The perception quickly becomes that the police are, at 
best, unable to keep them safe, or at worst, unwilling to. The 
Miami Police Department has successfully leveraged artificial 
intelligence over the past few years to great effect. We use 
gunshot detection systems, public safety cameras, facial 
recognition, or FR, video analytics, license plate readers, 
social media threat monitoring, and mobile data forensics. We 
use ballistic evidence to connect the dots between shootings 
and the violent actors that are victimizing our communities.
    A recent BJA-funded study by Florida International 
University, found that violent crimes are one such resource was 
used by our detectives, had a 66 percent greater likelihood of 
being solved when compared to similar cases where no such 
resource was used.
    I'm happy to discuss any of the technologies that we 
employ, but I'm going to take this time to discuss how we came 
to develop our policy governing the use of FR in criminal 
investigations. It started in January 2020, when The New York 
Times ran an article by Kashmir Hill. The article was critical 
of the use of law enforcement facial recognition, and of one 
vendor in particular.
    Ms. Hill posed several questions which resonated with me as 
I do spend my time out of uniform as a private citizen. Without 
proper safeguards, Ms. Hill asked, what would stop police from 
using FR to identify peaceful protest organizers, or 
cyberstalking an attractive stranger at a cafe? What about the 
public whose biometric data that is our faces would be analyzed 
by police?
    So my team and I set out to establish a facial recognition 
policy that would address these and other concerns. We're not 
the first law enforcement agency to use facial recognition or 
to develop FR policy, but we were the first to be this 
transparent about it. We did not seek to impose our policy on 
the public, we asked them to help us write it.
    We started out by meeting with local privacy advocates. 
They absolutely hated it, but we wanted to know why they hated 
it. So they told us. We found that many of their critiques were 
thoughtful and reasonable. So we heard their objections, took 
it upon ourselves to treat them as recommendations, and 
incorporated several of them into our policy.
    We highlighted successful arrests aided by FR through local 
media coverage, and that March, we held two virtual town hall 
style meetings virtually because in-person meetings were not an 
option due to the pandemic. One session was conducted in 
English, the other in Spanish. Each session included public 
questions and comments, and each session had about 1,300 live 
views in 3,600 total views.
    The policy that resulted from our effort created a narrow 
framework within which we would use FR. Most importantly, our 
policy emphasizes that FR matches do not constitute probable 
cause to arrest. Matches are treated like an anonymous tip, 
which must be corroborated by physical testimony or 
circumstantial evidence. We laid out five allowable uses; 
criminal investigations, internal affairs investigations, 
identifying cognitively impaired persons, deceased persons, and 
lawfully detained persons.
    We use FR retrospectively, that is, we don't use it in a 
live or real-time basis to identify persons going about their 
business in public spaces. And we do not use it to identify 
persons who are carrying out constitutionally protected 
activities.
    We establish a policy limiting who has access to our FR 
platforms, and we disclose our FR use to defense counsel in 
criminal cases. We do not substantively manipulate or alter 
probe photographs, use composite sketches as probe photographs, 
or use any other technique which has not been scientifically 
validated.
    These efforts, along with many others, resulted in a Miami 
that is safer today than in any other time in our history. I 
thank you for inviting me to speak before the Subcommittee, and 
I'm happy to answer any questions that you may have.
    [The prepared statement of Mr. Aguilar appears as a 
submission for the record.]
    Chair Booker. Thank you. That's extraordinary testimony.
    I remind the witnesses that Senator Whitehouse and Senator 
Kennedy are here, so you should be on your best behavior. Dr. 
Howard.

          STATEMENT OF MS. KAREN L. HOWARD, DIRECTOR;

         SCIENCE, TECHNOLOGY ASSESSMENT, AND ANALYTICS,

            U.S. GOVERNMENT ACCOUNTABILITY OFFICE, 
                      HUNTSVILLE, ALABAMA

    Dr. Howard. Chair Booker, Ranking Member Cotton, and 
Members of the Subcommittee, I am pleased to be here today to 
discuss technologies that can assist in criminal 
investigations.
    Criminal justice is an important governmental 
responsibility with a significant impact on the public. Such 
investigations should be conducted as quickly and accurately as 
possible. A number of algorithms can aid investigators in the 
search for links between individuals and evidence collected at 
a crime. Some of these tools are enabled by artificial 
intelligence, while others rely on statistical or automated 
methods rather than AI.
    My testimony today is based on two reports we issued, 
describing the strengths and limitations of the most common 
algorithms used for criminal investigations. In our work, we 
found that Federal law enforcement agencies primarily use three 
types of algorithms in their investigations; probabilistic 
genotyping, latent print analysis, and facial recognition.
    These algorithms offer some common advantages over human 
analysts. For example, they dramatically increase the speed of 
comparisons, allowing larger data bases to be searched in 
significantly less time. In addition, they generally produce 
more consistent results because they don't get tired or have an 
off day as human analysts can. The best of these tools are 
highly accurate and effective, often more so than a human 
analyst alone.
    However, this is not to say that such algorithms are 
perfectly accurate or objective. There are hundreds of 
algorithms in development and on the market, and performance 
can vary significantly among them as shown in independent 
testing by the National Institute of Standards and Technology, 
NIST. Studies have shown that the best results may be obtained 
from the combination of a highly accurate algorithm and a well-
trained analyst.
    Despite the advantages offered by high quality algorithms, 
there are also several challenges to their use. For example, 
poor quality crime scene evidence can significantly increase 
the effectiveness of the tools, and experts told us there is 
considerable variability in the standards for what constitutes 
suitable evidence quality, especially across the many State and 
local law enforcement agencies.
    Other challenges include errors or improper use by human 
analysts, unknown and potentially biased training data for AI-
based algorithms. The possibility that the correct person isn't 
in the data base used for comparison. Difficulties with 
interpreting and explaining the output. Lack of the necessary 
information for law enforcement agencies to identify the best 
performing algorithms, and sometimes a lack of resources to 
purchase those. And a lack of public trust in the results for 
some algorithms.
    We proposed three policy options that may help address 
these challenges. First, increased training for analysts and 
investigators, which could improve their understanding of the 
importance of crime scene evidence quality. Increased training 
could also reduce errors and inconsistency by human analysts 
and increase proper interpretation of algorithm results.
    Second, policymakers could facilitate the development and 
adoption of standards for appropriate use, which could set 
standards for algorithm performance that is acceptable, reduce 
the use of low-quality evidence, and increase public confidence 
in the results.
    And third, increase transparency regarding the testing, 
performance, and use of algorithms, which could make it easier 
for law enforcement entities to identify the best performing 
technologies, and improve understanding of the training data 
for AI-enabled tools, perhaps leading to the development of 
more robust and representative training data.
    Finally, I note that there are many other types of 
algorithms in development or use beyond the three we examined. 
Some of these depend on AI to power their comparisons and 
decisionmaking. In our judgment, the challenges we identified 
are likely to also be relevant to these other types of 
algorithms.
    In conclusion, we found that probabilistic genotyping, 
latent print analysis, and facial recognition can be very 
useful to help investigate crimes, but several challenges may 
limit their effectiveness. By addressing these challenges, we 
can improve the accuracy and effectiveness of criminal 
investigations and enhance public trust.
    This concludes my prepared statement, and I would be happy 
to respond to any questions.
    [The prepared statement of Dr. Howard appears as a 
submission for the record.]
    Chair Booker. Dr. Howard, I'm really grateful. Professor 
Wexler.

                STATEMENT OF MS. REBECCA WEXLER,

                  ASSISTANT PROFESSOR OF LAW,

                  UC BERKELEY SCHOOL OF LAW, 
                      BERKELEY, CALIFORNIA

    Professor Wexler. Mr. Chairman, and Members of the 
Subcommittee, my name is Rebecca Wexler, and I am a co-director 
of the Berkeley Center for Law and Technology, and an assistant 
professor of law at Berkeley Law School. I'm honored to testify 
here today about the need for fair and open proceedings to 
scrutinize AI tools used in the criminal legal system.
    Although AI tools present exciting opportunities to render 
the legal system more accurate and equitable in some respects, 
they also present troubling obstacles to fair and open 
proceedings. To help fix this problem, Congress should do two 
things. First, require that AI tools used in the criminal legal 
system be made available for auditing by independent 
researchers with no stake in the outcome. Second, prohibit 
either party in a criminal case from invoking the so-called 
trade secret privilege to block access to relevant evidence, 
and instead require that such evidence be disclosed under a 
reasonable protective order.
    Zooming out, the U.S. criminal legal system is a model to 
the world in its commitment to fair and open proceedings to 
protect against wrongful convictions. That reputation rests on 
the safeguards we offer those accused of crime, including a 
fair opportunity to uncover weaknesses in the government's 
evidence of guilt, and to expose unlawful and unconstitutional 
police conduct.
    This is why the Sixth Amendment guarantees the accused the 
right to confront witnesses against them, and to compel 
witnesses in their favor. It's why due process and statutory 
discovery laws require prosecutors to disclose evidence to the 
defense. It's why the Supreme Court has directed judges 
deciding whether to admit scientific and technical evidence, to 
consider whether the evidence has been subject to peer review. 
Fair and open proceedings in which evidence is subject to 
robust and independent adversarial scrutiny are necessary for 
accurate, accountable, and legitimate criminal investigations 
and prosecutions.
    These transparency commitments are all the more important 
in the emerging age of AI because we are together facing a new 
form of evidence that by its nature, cannot be scrutinized with 
the tools that parties have traditionally used, such as cross-
examination and classic detective work. In turn, allowing AI to 
enter criminal courtrooms without sufficient scrutiny is 
dangerous.
    While AI has the potential to improve law enforcement 
efficacy, it can also cause harmful errors with high-stakes 
consequences for life and liberty. For instance, erroneous AI 
face recognition hits and gunshot alerts have led to multiple 
alleged wrongful arrests and imprisonment. A recent study found 
that state-of-the-art AI photo forensic program, performed 
worse than regular people with no special training, and two DNA 
analysis forensic software programs came to divergent results 
about whether a defendant's DNA was included in a crime scene 
sample in a homicide case.
    We need fair and open proceedings to expose these kinds of 
costly mistakes and discrepancies. Unfortunately, some vendors 
block independent review that might expose flaws in their AI 
products. For instance, consider probabilistic genotyping 
software, the GAO Office, the PCAST report, and NIST all 
expressed concern about the lack of independent review of these 
tools. Yet, when fellow academic researchers and I sought to 
purchase a research license to study one of them, the vendor, a 
company called Cybergenetics, told us, ``Cybergenetics does not 
provide research licenses.''
    Representatives of this company have testified under oath 
in courts across the country that their product is subject to a 
peer review process and hence its output should be admissible 
in criminal cases. But when we actually tried to perform 
independent research into quality assurance and validation, the 
company stopped us from doing it.
    Congress should require vendors to allow independent audits 
by clarifying that AI tools used in the criminal legal system 
must be subject to independent review. There's an important 
role for Congress here to authorize Federal grants for law 
enforcement agencies to purchase AI systems only if the vendors 
make them available for auditing by research groups with no 
stake in the outcome.
    In another obstacle to fair and open proceedings, some 
vendors have also relied on a so-called trade secret privilege, 
to refuse to disclose details about how their technologies work 
to criminal defendants and expert witnesses, even under a 
protective order, and even in capital cases where the risk of 
error is wrongful death.
    This should not be happening. We need criminal defense 
counsel and experts, as well as judges and prosecutors, to 
scrutinize AI systems to ensure accuracy and fairness. There's 
no good reason for trade secret law to block this crucial 
process. Once again, there's an important role for Congress to 
clarify that no trade secret privilege exists in federal 
criminal cases, and relevant evidence must be disclosed under a 
protective order.
    Thank you for the opportunity to testify here today.
    [The prepared statement of Professor Wexler appears as a 
submission for the record.]
    Chair Booker. Thank you for the strong testimony. I'm here 
for the duration, so I'm going to go to Senator Butler. Then 
we're going to come back and go to the Ranking Member, Cotton. 
Then we're going to go to Whitehouse, and unless some nobody 
else comes, I will followup in the end. But we'll go to Senator 
Butler representing the great State of California.
    Senator Butler. Thank you, Senator Butler--you can be 
Senator Butler, too.
    Chair Booker. Hey, Butler's a kick up.
    Senator Butler. Senator Booker, thank you so much, and to 
our Ranking Member for hosting such an important conversation. 
I will sort of skip the preface and really jump right into what 
I think is a very important topic to examine. Dr. Howard, if 
it's okay, I'll start with you, and I'll try to land in my 
constituents' basket there.
    But Dr. Howard, you mentioned in the three recommendations 
that you would invite Congress to act in this space of 
increased transparency. I'd like to hear you talk a little bit 
about what kinds of transparency you think are needed. I'm 
going to direct this question to Professor Wexler as well, but 
I'd love to start with you and just sort of hear your thoughts 
there.
    Dr. Howard. Certainly, and we, in making our policy options 
for policymakers, we try not to be too prescriptive----
    Senator Butler. Sure.
    Dr. Howard [continuing]. We want to leave room for the 
policymakers, but some of the things we heard about from 
experts we spoke with include being transparent about the 
training data bases. For example; how representative are they? 
Where are they drawn from? Are they representative of the kind 
of evidence that might be collected at a crime scene? The sort 
of print quality that might be expected, or photo quality that 
might be expected.
    Also, increased transparency about whether they've been 
tested, and how, and what were the results of those tests so 
that everybody understands how does the algorithm perform under 
ideal conditions, under less-than-ideal conditions, which are 
often present in a criminal investigation? And can then make a 
determination about how much weight to give the evidence that 
is produced by the algorithm?
    Senator Butler. And then, Professor Wexler, what would you 
add to it? I know there are a couple of specific areas that you 
also recommend increased transparency. You ended your testimony 
in the space of auditing. What other recommendations would you 
add there?
    Professor Wexler. Thank you for the question. I would add 
that the right test is the baseline relevance test. So by 
default, criminal defense counsel is entitled to discover 
relevant evidence on a case-by-case basis. That's the threshold 
that they should have to show in order to get access to any 
details about evidence used against their client.
    What's the problem is when that threshold burden is raised 
to a necessity burden, for instance, based on some so-called 
secrecy interest. And the secrecy interest, if it's 
intellectual property, is not a legitimate one to do that.
    Senator Butler. So stay, stay there for just 1 second 
because I did want to talk just a little bit about public 
defenders. And we all know, have seen the data, particularly in 
metropolitan communities around the country, the overworked 
nature and caseload management of public defenders. You talk a 
lot about the potential challenges, the need for transparency. 
Share just a little bit about how the failure to disclose the 
usage of AI might enter the consideration or the management of 
the case workload for public defenders.
    Professor Wexler. Sure. So I have two thoughts on this. One 
is that because AI systems are used across many different 
cases, even if you have a public defender, or even private 
defense counsel who's particularly well-resourced, so say in a 
centralized office that has enough counsel to have specialized 
counsel focusing on DNA or other forensic technologies, even if 
disclosure goes just to--if it goes to everybody, but those 
well-resourced counsel are able to identify flaws or weaknesses 
in the technology, those identifications benefit everyone as a 
whole.
    So even though not every counsel will have the bandwidth to 
address it, disclosure is still beneficial. And I can give a 
concrete example of where disclosure was beneficial in one 
case, if that would be helpful. The Office of the Chief Medical 
Examiner of New York City created a forensic software program 
called FST to analyze DNA evidence. And for years, they refused 
to disclose source code for that tool, claiming they had a 
trade secret interest in withholding it.
    In one case, they finally were ordered to disclose by Judge 
Valerie Caponi, former general counsel of the FBI in the 
Southern District of New York. And the defense expert witness 
who reviewed it in that case uncovered a undisclosed function 
that discarded data in certain circumstances, and had been 
added after the New York State Forensic Science Commission's 
regulatory approval for the tool. So that discovery happened in 
an individual case and was beneficial, was useful information 
for many other defense counsel as well.
    Senator Butler. Thank you so much, and thank you, Mr. 
Chair.
    Chair Booker. Thank you very much, Senator. Ranking Member 
Tom Cotton.
    Senator Cotton. Mr. Aguilar, you mentioned in your opening 
testimony that tip lines are like Crime Stoppers. You had also 
said last year in the interview that your department treats 
facial recognition technology, ``like a tip that is called into 
Crime Stoppers.'' Is that correct? Do you recall that?
    Mr. Aguilar. Yes, Senator.
    Senator Cotton. So in your career as a police officer, have 
you ever gotten erroneous tips from Crime Stopper hotlines?
    Mr. Aguilar. At least tips that we couldn't corroborate 
with other evidence. Absolutely, Senator.
    Senator Cotton. Okay. Have you ever considered eliminating 
Crime Stopper hotlines because you get erroneous tips?
    Mr. Aguilar. Absolutely not.
    Senator Cotton. Okay. You're not testifying that, say, 
facial recognition technology or ballistic technology is 
flawless. Are you?
    Mr. Aguilar. I'm not.
    Senator Cotton. Okay. Let's say that you have facial 
recognition technology, and you run a security camera image 
through that technology, and it gives you back seven potential 
positives. What's the next steps do you take? Do you go out and 
arrest all seven individuals?
    Mr. Aguilar. Absolutely not, Senator. We would treat the 
matches as if we had just received seven Crime Stoppers tips, 
and our detectives would do their due diligence, and either try 
to discount or corroborate it with other evidence that could 
tie that person to the crime scene
    Senator Cotton. Using other technology or even artificial 
intelligence technology or using traditional gumshoe 
investigative techniques?
    Mr. Aguilar. All of the above, Senator. This is absolutely 
not a substitute for traditional investigative methods. It 
compliments traditional investigative methods, but in no way 
can AI, at least in my view, substitute traditional methods.
    Senator Cotton. Okay. What would be the consequence if you 
did not have this kind of technology in your department?
    Mr. Aguilar. I'm very certain that we would have many more 
crimes that would go not only unsolved, but there's an 
additional consequence to having unsolved crimes, and that is, 
that those criminal suspects are allowed to continue to 
victimize other people. And so it's not just a lower clearance 
rate, but it's also a higher victimization rate.
    Senator Cotton. Okay. Ms. Wexler, one of your chief points 
seems to be that the vendors who provide such technology should 
be compelled to disclose their source code. Is that correct?
    Professor Wexler. If the source code is relevant evidence 
in a particular case, then that should be the baseline 
standard, and should be disclosed under a protective order that 
protects the intellectual property interest to a reasonable 
degree.
    Senator Cotton. Could you give examples, again, of when 
that would be relevant evidence? Because as Mr. Aguilar said, 
if you get seven positives from facial recognition technology, 
that itself is not going to be what cinches is the case, or 
gets a conviction, or perhaps even admitted into court. It's 
going to be the follow-on investigative techniques that his 
detectives use.
    Professor Wexler. Sure. So relevance means any evidence 
that makes the fact at issue in a case more or less likely than 
it would be without the evidence. So it's actually a pretty low 
bar. I tell my students a brick is not a wall. So evidence 
doesn't have to disprove the whole case in order to be 
relevant. It just needs to weaken or strengthen one element of 
it. So any information about how a forensic technology works 
that could expose unreliability of a particular match would be 
relevant.
    Senator Cotton. Let's use something a little more high tech 
than, say, facial recognition, which we all engage in every 
single day, let's say ballistic matching. If you have AI-
assisted ballistic matching, is that the source code of that 
technology that's what's relevant, or is it going to be the 
human testimony that follows on that, presumably, from dueling 
witnesses the State uses and that the defense uses? Does the 
source code matter once you have those dueling witnesses in the 
follow-on question?
    Professor Wexler. So various aspects of the technology 
might be relevant in a particular case. A source code might not 
always be relevant, but it could be in a particular case. Even 
if an AI technology is then being reviewed, the conclusions are 
reviewed by a human witness, the AI results may have bias to 
the human witness.
    So it'd be important to understand if they were flawed. AI 
results may, in face recognition technology, produce alternate 
candidate lists that could be exculpatory evidence that would 
need to be disclosed to the defense. So those are examples.
    Senator Cotton. Why do you think these vendors don't want 
to disclose your source code to you and your fellow law 
professors or to criminal defense attorneys?
    Professor Wexler. So to be clear, my fellow academic 
researchers----
    Senator Cotton. And you-all wanted a license. Why do they 
not want to give you a license to use it, and why do they not 
want to disclose it to criminal defense attorneys?
    Professor Wexler. In my personal view, and of course I 
don't have insight into their own heads, is that they are 
concerned about subjecting their products to robust adversarial 
scrutiny because that scrutiny might expose weaknesses or flaws 
in their tools.
    Senator Cotton. And these products have undergone testing 
by, say, our own Department of Justice. Haven't they?
    Professor Wexler. Some of the products have undergone 
testing and some of them less so. So in terms of probabilistic 
genotyping software programs, again, the GAO Office, NIST, the 
PCAST report have all identified concern that much of the 
testing was not performed by independent researchers. And most 
recently, NIST identified that some of the published validation 
studies don't have enough publicly available data to be 
independently verified.
    Senator Cotton. Mr. Aguilar, do you have any thoughts on 
why these vendors might not want to disclose their source code 
to criminal defense attorneys, or provide research licenses to 
professors?
    Mr. Aguilar. Senator, I cannot speak for the vendors. I can 
only imagine that there's at least some concern over 
intellectual property, but I certainly cannot speak for the 
vendors.
    Senator Cotton. Okay. And Professor Wexler, you keep saying 
protective order. There, you're talking about disclosure of 
source code in a criminal proceeding. Right?
    Professor Wexler. It could be disclosure of any aspect of 
the technology. So vendors, these companies, have actually 
alleged that trade secret privileges should apply to all sorts 
of aspects of these tools, including things like user manuals. 
So, it's not limited to source code.
    But I will say that, you know, courts order disclosure of 
intellectual property under protective orders, reasonable 
protective orders all the time. It's a common solution in civil 
cases, and if it's effective there, it should also be deemed 
sufficient in criminal cases where the stakes are life and 
liberty.
    And I'll add that protective orders give intellectual 
property holders more safeguards than the non-disclosure orders 
that companies usually--non-disclosure agreements, I'm sorry, 
that companies usually disclose the same information under for 
when they share it with their employees or with business 
negotiators.
    So the protective order, if there were to be a leak, rare 
instance, there's not evidence that protective orders are 
generally violated or commonly violated. But in the rare 
circumstance where that might, happen trade secret holder would 
still be entitled to sue for misappropriation of their 
intellectual property.
    And on top of that substantive trade secret guarantee, 
there would be the additional guarantee of criminal or civil 
contempt of court plus the possibility of disciplinary 
sanctions if it were an attorney who violated the protective 
order. So given those safeguards, trade secret law does not 
provide a good reason to withhold relevant evidence in a 
criminal case.
    Senator Cotton. Mr. Aguilar, in your long history of 
criminal proceedings, has a protective order ever been 
violated?
    Mr. Aguilar. No instances come to mind, Senator.
    Senator Cotton. Okay. Thank you.
    Chair Booker. Thank you for that really thorough 
questioning. Senator Whitehouse.
    Senator Whitehouse. Could I ask each of you to consider in 
the law enforcement arena what you believe to be the most 
promising use of AI that we in Congress should consider 
encouraging, and what you consider to be the most dangerous use 
of AI that we should be more closely monitoring? Just go right 
across, if you don't mind, Aguilar, to Howard, to Wexler.
    Mr. Aguilar. Senator, it's very difficult to list any one 
that has the most promise, and I can cite several examples 
where we've successfully solved everything from violent crimes 
to property crimes using a number of AI tools. I think that the 
greatest threat comes in the absence of sound policy, and that 
applies to any tool that law enforcement uses.
    So again, sometimes we may think of AI as something new and 
a challenge that we've never faced. But the reality is that law 
enforcement has, for many years, had access to sensitive 
information through driver's license data bases, criminal 
records, and it's the policy around those systems that really 
safeguards the public.
    The same can be said for other tools that we use; our 
weapons, our vehicles. We don't rely on manufacturers to write 
our deadly force policies or our driving policies. So I think 
that the absence of policy would pose the greatest threat, and 
Congress should be looking at a number of AI tools that are 
right now making our community safer.
    Senator Whitehouse. Dr. Howard.
    Dr. Howard. The only AI-enabled tool that we examined in 
any detail was facial recognition, but I would say broadly, the 
most promising AI tools are those that are trained on a 
reliable and representative data set that is well understood, 
and that is----
    Senator Whitehouse. Like ballistic information?
    Dr. Howard. We have not studied that one. So I can't affirm 
that, I'm sorry.
    Senator Whitehouse. There's plenty of it though.
    Dr. Howard. And that also I have a well-trained analyst and 
investigator using them, because remember, every AI tool is the 
middle piece of an evidence process. Somebody collects crime 
scene evidence, prepares it for use, determines whether it's a 
suitable quality to be inserted into the algorithm, and then 
assesses the output that comes out of the other end and decides 
what to do about it. So that well-trained analyst is key.
    The riskiest AI tool would be one where the training data 
set is not understood, not representative, and it's being 
handled by somebody who really doesn't understand what the 
technology is and isn't telling them in the output.
    Senator Whitehouse. Thank you. Professor Wexler.
    Professor Wexler. I think that it would be promising for 
Congress to support AI that is aimed at uncovering exculpatory 
evidence. One of the concerns that I have about the markets for 
AI tools is that most of the paying customers are law 
enforcement, and defense experts and defense investigators 
don't have the same money to throw at the problem. And this may 
bias the development of technologies in favor of identifying 
evidence of guilt rather than identifying evidence of 
innocence.
    So any support Congress could give to AI technologies 
designed to identify evidence of innocence would be very 
promising, and my biggest concern are technologies that are 
kept secret and withheld from adversarial review by the 
vendors.
    Senator Whitehouse. And Mr. Aguilar, you might have 
mentioned this, but with your experience on law enforcement, 
have you had occasion to use any kind of AI technologies with 
ballistics information, with cartridges, spent bullets?
    Mr. Aguilar. Absolutely, Senator. So with our partnership 
with ATF, we do have an in-house ballistics program, a crime 
and gun intelligence center. And it's one of many tools that we 
employ to investigate and prevent violent crimes. It's 
certainly been helpful.
    Senator Whitehouse. Is there an AI component though? 
Because before there was AI, there were still computer programs 
that compared, for instance, the markings on an ejected 
cartridge or the markings on a spent bullet. Two other markings 
in the same way that fingerprint searches take place. Not so 
much with modern AI, it's just computer data bases.
    Mr. Aguilar. So our definition of AI sometimes changes. 
Right? As technology becomes more mainstream, we sometimes 
think of it as less AI than the newer technologies. But if we 
look at ballistic evidence where it's compared through an 
automated system in a data base, and then later it has to be 
verified by a human analyst, and it makes connections through 
the automated process that has to later be verified by a human 
analyst. So in that sense, I certainly consider it AI as it has 
to be human-verified.
    Senator Whitehouse. Thanks very much, Chairman.
    Chair Booker. Thank you very much. I'm not sure who was 
here first. Padilla. California is well represented today. 
Senator Padilla.
    Senator Padilla. Thank you, Mr. Chair. Speaking of 
California, it was recently reported that a local police 
department in my State used AI to render a 3D image of a 
suspect from crime scene data DNA, and then attempted to run 
that image through facial recognition software in an effort to 
identify a suspect.
    Now, this is the first reported case of law enforcement 
attempting to use facial recognition technology, which has 
questions in and of itself, on an AI-generated image. The 
incident first occurred, actually, in 2020. So it's been a 
couple of years, but the public did not become aware of it 
until it was reported this week. There appears to be a little 
transparency questions and concerns about how AI tools are 
being used by police and prosecutors during criminal 
investigations. And I cited just one example.
    First question is for Dr. Howard. What steps should be 
taken to ensure that defendants and the public are aware of 
when AI is being used in criminal investigations?
    Dr. Howard. Part of our policy option calling for 
transparency would envision a scenario where it is revealed 
when algorithms have been used in one form or another. And to 
speak to Mr. Aguilar's point, AI is often what we now think of 
as automated technologies, was originally considered AI, what 
most people call AI now is machine learning, which is trained 
on training data. We believe that transparency step should be 
known. People should be aware when an algorithm has been used 
in one form or another as part of the evidence collection and 
assessment process.
    We do believe, however, it's very important to validate the 
results of those methods. And in this case, the articles that 
I've read have not indicated whether any validity testing has 
been conducted on the reconstruction process for the face, and 
then whether those faces can be reliably run through even the 
best algorithms. We've not seen any data indicating that those 
have been tested.
    Senator Padilla. Exactly. So it brings up a whole host of 
questions. Followup question for Professor Wexler. Welcome from 
California. How critical is transparency for fostering a 
positive relationship between citizens and law enforcement for 
ensuring just results in criminal proceedings?
    Professor Wexler. Transparency is crucial for a positive 
relationship between citizens, law enforcement, and just 
results in criminal proceedings. Transparency is one of the key 
functions of the adversary system. We have an adversary system 
to enable the criminally accused to scrutinize and contest the 
evidence against them so that we can ensure that law 
enforcement's use of that evidence is effective, accountable, 
and legitimate.
    Senator Padilla. Now, question on a separate topic. Last 
September, the GAO released a report showing that several 
Federal law enforcement agencies, including the FBI and DEA 
among others, did not require their agents to be trained on 
protecting civil liberties and rights when using facial 
recognition software.
    As I mentioned earlier, facial recognition software begs a 
whole host of questions in and of itself. But this lack of 
training is troubling, given that the technology has been shown 
to produce biased results, particularly when it involves 
identifying black and brown persons. Back to Dr. Howard, since 
the release of this publication, have steps been taken to 
ensure that Federal agents are trained on how to responsibly 
use facial recognition technology?
    Dr. Howard. We are not aware of any changes as a result of 
that report. That doesn't mean they haven't occurred. We just 
have not been able to followup with the agency to see whether--
--
    Senator Padilla. So then the bottom-line----
    Dr. Howard [continuing]. They've been trained.
    Senator Padilla [continuing]. Question is; what 
recommendations do you have to this committee, to the Senate to 
Congress, to advance this?
    Dr. Howard. One important feature of facial recognition is 
the need to test and verify the accuracy and the demographic 
bias. And this is one of the things that NIST does in its 
testing, but NIST does not exhaustively test every algorithm. 
It tests the algorithms that are submitted to it for testing.
    So, one possibility would be to require algorithms to be 
tested through an independent third party, such as NIST, if 
they're going to be used for Federal law enforcement purposes, 
that would add that measure of third-party independent 
accountability. If you're using the best tools, can an error 
still occur? Of course. Human beings make lots of errors as 
well, and many of the most highly publicized errors with 
forensic algorithm tools have actually been traced back to 
errors the human analyst made, for instance, submitting 
evidence that was not of high-enough quality to the algorithm, 
and the algorithms then unable to give a reliable result.
    Senator Padilla. Right. And you have confidence that NIST 
or any, whichever Federal entity ends up with this 
responsibility, has a capacity for determining guidelines for 
testing and certification of algorithms?
    Dr. Howard. We've not looked at that directly, but we do 
know that NIST is often tasked with the job of setting 
standards for such things and would seem to have the----
    Senator Padilla. That's the flip side. Right? You can do 
test all you want, but what are you testing for in determining 
what passes and what doesn't. Okay. Thank you. Thank you, Mr. 
Chair.
    Chair Booker. I think when you get two parts, California, 
one part Georgia, that is New Jersey, but.
    [Laughter.]
    Chair Booker. So with that, Senator, you have to bake at 
350 for about 45 minutes. But Senator Ossoff, thank you very 
much. Please proceed.
    Senator Ossoff. Thank you for convening us, Mr. Chairman, 
and thank you to our witnesses for your expertise.
    Beginning with you, please, Professor Wexler, what 
technologies or practices are being developed, or might need to 
be developed to make criminal investigations, law enforcement 
activity, civil litigation resilient against synthetic, 
fabricated evidence?
    There's much discussion about voice cloning and the rapid 
advance in that technology. You can imagine that being provided 
by a malicious third party to law enforcement to prompt a 
criminal investigation of a targeted individual, or other cases 
where such technology could be used to frame or improperly 
implicate somebody. How do you protect against that risk, and 
do you think it's right to think of that as a risk?
    Professor Wexler. Oh, I think it's absolutely a legitimate 
concern. And it raises the question of whether our current 
legal system and current evidence rules are up to the task of 
maintaining accuracy and adversarial review with new 
technologies like deepfake technologies available.
    So when AI-produced evidence or AI-analyzed evidence comes 
into court, risks of error are present just as they are with 
human witnesses. And yet, one of the new challenges is that 
some of the traditional safeguards we have for cross-examining 
human testimony don't apply to machine-generated outputs. So 
it's very difficult to put a AI output on the stand under oath 
and cross-examine them, and observe their demeanor. That's not 
going to work.
    So the technology, I would say, as a lawyer, that we need 
to develop to ensure proper safeguards is the legal technology 
of ensuring we have robust discovery and transparency rules 
available, perhaps more pretrial testing, access to these 
technologies for validation and scrutiny rather than simply 
relying on the current evidence rules as they exist.
    Senator Ossoff. Where AI is used for purposes of 
investigative analysis, transparency and discovery through the 
adversarial process could be sufficient. But what about 
verification? The verification of the veracity or authenticity 
of evidence that's presented in court?
    Professor Wexler. So for evidence presented in court----
    Senator Ossoff. Or let me say, or if it's presented as a 
predicate to open a criminal investigation prior to even 
arriving or perhaps never arriving in court?
    Professor Wexler. Excellent. So, right, as an evidence 
professor, I always have to tell my students, the evidence 
rules don't even apply if you never get to court. So what are 
you going to do? And there I would say, we really need 
independent researchers with no stake in the outcome to be able 
to have access to these technologies to test, and scrutinize, 
and validate them.
    And so one of the things that Congress could do here is 
require or incentivize through the Federal grants program for 
law enforcement assistance that AI technologies used in the 
criminal legal system are open to peer review or scrutiny by 
independent researchers with no stake in the outcome. And that 
will help with that verification piece, even before we get to 
trial.
    Senator Ossoff. And thinking about the rules of evidence 
and discovery, if synthetic and inauthentic evidence were used 
to open a criminal investigation, and the subsequent progress 
of the investigation yielded for criminal investigator 
sufficient evidence to prosecute, and the initial underlying 
inauthentic and synthetic evidence that was used to justify the 
progress of the investigation is never presented in court. 
Would a criminal defendant ever have means of knowing that at 
the very beginning of the process that led them to this 
position was something artificial or synthetic?
    Professor Wexler. Under current law, I don't believe there 
would be a requirement to disclose. There's not a clear path 
for that, and that's a concern. There's a process called 
parallel construction where law enforcement may undergo 
multiple investigations, and present one path toward finding 
evidence in court and not disclose the other paths. So there 
may be an opportunity and a role here for Congress to mandate 
affirmative disclosures of investigative strategies.
    Senator Ossoff. And that's a concern as well, isn't it, 
where foreign intelligence information may be the root of a 
criminal investigation, but through parallel construction, 
sufficient evidence is developed by investigators and 
prosecutors such that the origins of the investigation being 
rooted in foreign intelligence is never disclosed to the court 
or to the defendant.
    Professor Wexler. There certainly are concerns about that. 
Yes.
    Senator Ossoff. Dr. Howard, any thoughts on verification of 
evidence? Think about deepfakes voice cloning.
    Dr. Howard. So we've done limited work on deepfakes. It was 
not a part of the work I'm testifying about today, but the fact 
that the current state technology is able to detect deepfakes, 
it sometimes takes time. It's not necessarily a quick process. 
And with deepfakes, that can be an issue if something is out in 
the public and causing harm, and we can't identify it quickly 
enough.
    In the cases you're talking about, criminal investigations 
can take a long time, prosecution can add time to that as well. 
So one would hope the technologies would allow us to identify 
synthetic evidence before it were brought to court, for 
example, in the case that Professor Wexler might be 
hypothetically talking about.
    But the tools in any kind of a fraud-type scenario, the 
tools are almost always a step behind the fraudsters. They're 
creating some new way to do something, and those who are trying 
to detect it are just a step behind them.
    Senator Ossoff. One more question.
    Chair Booker. Of course. Go ahead.
    Senator Ossoff. So, or as Professor Wexler noted, the 
underlying synthetic evidence may never be brought into court, 
may never be scrutinized, may never be subject to verification. 
Dr. Howard, is your impression that the technology--have you 
done any study, do you have a sense of whether the technology 
for verification, for detection of synthetic evidence such as 
voice cloning is expected to stay ahead of the capacity for 
synthesis and production of deepfakes, or are we expecting 
instead that the apparent authenticity of deepfakes will become 
so sophisticated, so advanced that it defies verification?
    Dr. Howard. We don't have any direct evidence either way, 
but historically speaking, the detection tools are normally 
just a step behind the new creations of ways to perpetuate 
fraud. One might assume the same would occur here, but we have 
no evidence of that in either direction. We don't see any 
evidence at the current time of something being created that's 
totally undetectable. It just may take time.
    Senator Ossoff. Thank you. Thank you, Dr. Howard. Thank 
you-all.
    Chair Booker. Thank you very much. Professor Wexler, I 
really do question whether Senator Cotton has seen WALL-E. But 
otherwise, I actually think he's a really intellectually 
rigorous--and I don't always agree with his conclusions, but 
he's an intellectually honest person, and I think where he was 
going is really substantive, which is this idea of somehow the 
AI technology companies that we're talking about, that you 
rightfully asked for, you know, adversarial scrutiny, peer 
reviews, and how urgent it is for us to get over this trade 
secret privilege.
    I guess the concern that, I think, that he was getting at 
was that those companies do have a legitimate--and again, might 
be cynical to say that they're just interested in being able to 
continue to sell their product. But you had some good retort 
for the idea, and I want to scratch it a little bit more, that 
those companies get more protection by opening themselves up to 
that scrutiny. Could you just explain that to me a little bit 
more?
    Professor Wexler. Sure. Absolutely. So substantive trade, 
secret law is a body of intellectual property that creates a 
negotiation between the public interest in accessing 
information and the goal of incentivizing innovation by 
providing property rights to the owner. And so there are 
limitations all the time to substantive property rights. Patent 
law has an expiration date, and trade secret law has some 
limitations as well that are part of that policy balance. The 
limitation of trade secret law is that you only get a right 
against misappropriators, which is wrongful acquisition, use, 
or disclosure.
    And my position is that cross-examination in court is not 
misappropriation. So the only time the intellectual property 
interest would kick in is if somehow a protective order, if 
information's properly disclosed under the protective order 
subject to cross-examination for purposes of a criminal case, 
that limited case, could be attorney's eyes only, expertise 
only. The only reason that a company might have a legitimate 
concern is if that protective order might leak.
    And what I was trying to explain, and I'm happy to have 
another opportunity to elaborate, thank you, is that in that 
unlikely event, and there's not evidence that this happens 
regularly, in the unlikely event that a trade secret were to 
leak when it was subject to a protective order, all of the 
substantive trade secret protections are still available to the 
intellectual property owner. They can sue for misappropriation, 
and yet, there's even more safeguards than normally occur 
outside of court because you have criminal contempt of court 
charges.
    Chair Booker. Okay. So I understand that, and that's 
really, I think, a substantive point. And so to the extent you 
can, the only jeopardy there is you don't see any real business 
pecuniary jeopardy to that person exposing their algorithms or 
their processes to peer review. You really can't think of any 
other business threat to them because, clearly, they're getting 
some additional safeguards. Is that what you're saying?
    Professor Wexler. Correct. There's no legitimate business 
concern with disclosing the information for cross-examination 
under protective order for the limited purpose of ensuring 
accuracy in a criminal case.
    Chair Booker. And then what about a prosecutorial concern? 
In all sincerity, could there be a concern amongst the 
prosecutors?
    Professor Wexler. I believe that the trade secret privilege 
should not be available to either party to claim in a criminal 
case, so that this would be a parallel and equal requirement of 
disclosure.
    Chair Booker. Okay. Let me take off my Senator Cotton hat. 
He does a much better job at being Senator Cotton than I do. 
Although I can ask the staff, maybe, am I stepping up to the 
plate?
    And now let me ask one of my concerns, which is 98 percent 
of criminal convictions is done during plea bargaining and has 
nothing to do with trial. And I'm wondering about this element 
that you said where--and Senator Cotton did a good job, I 
think, also of bringing out this fact that as Chief Aguilar 
said that, well, the AI gets me to a point, but my analysts, 
and my experts, and my good gumshoe police work--I need to know 
where that gumshoe, like, where does that come from? Is there 
really gums on their shoes. Explain this to me someday, please. 
But that it really is not--I'm not relying solely on the 
technology. This has now been reviewed by expert human 
witnesses. So that renders your desire to break open my 
algorithm and all of that moot, because now it only led me to 
knowing it's one of seven people. Why should I be subject to 
that kind of scrutiny now?
    Professor Wexler. Great. So I have two responses. The first 
is to say defendants or prosecutors are only entitled to 
discover relevant evidence. So if information truly is moot, in 
other words, there's no possible way that disclosing the 
information could render a fact at issue, more or less likely 
than it would be without it, it's not discoverable. It's 
already protected. You don't get it. So we're only talking 
about relevant information.
    Now, my second point is there may be all sorts of 
circumstances where it could be relevant to discover 
information about the algorithm, despite the fact that a human 
has reviewed it after the fact. And I certainly can't 
anticipate all those circumstances on a case-by-case basis, but 
I can think of a few.
    An example would be if the algorithm, say a face 
recognition system, were known to the analyst who's reviewing 
it, and potentially biased to that analyst to have 
overconfidence in their conclusion, you'd want to know then 
whether it was overconfidence, how good was that algorithm? 
Were they right to trust it so much?
    Another example might be that the algorithm could have 
produced alternate exculpatory information that wasn't 
disclosed by the human analyst because it didn't fit with the 
analyst's own conclusions. And that could help as well.
    Chair Booker. A brilliant point. And so the last thing I 
would ask you is you said you give your law students this, 
``the brick is not the wall.'' Can you explain that to me 
again? Because I went to Yale Law School, as you know, that's 
an inferior law school compared to Boalt, but go ahead.
    Professor Wexler. Yes, thank you. You know, I don't even 
know where the phrase comes from, but a brick is not a wall 
means relevance is a relatively low bar. It doesn't mean 
nothing, but it's not an onerous threshold like showing that 
this piece of evidence is going to prove your whole case, no. 
It just means you get information, and you get to introduce it 
in court if it will make a fact, an issue ever so slightly more 
or less probable. And then with all those individual pieces of 
information, all those little bricks that are each relevant on 
their own, you build a case.
    Chair Booker. Right. And then finally, there's this big--
there's a great book ``Why Innocent People Plead Guilty.'' 
Because they face such an enormous stacking of criminal charges 
and the enormity of it all. And I guess we could imagine a 
situation where a prosecutor is sitting there saying, ``Take 
this deal. We'll give you 5 years, or else you're going to face 
50, because we've got this evidence based upon AI.'' That's a 
very intimidating moment for an overworked--as one of my 
colleagues was saying--defense attorney. Is that a concern of 
yours?
    Professor Wexler. Absolutely a concern. I absolutely agree. 
And I'll just add to this concern that many indigent defense 
counsel may not have the resources to challenge the AI, but 
also individual defendants might--the cost of fighting the 
case, even when they maintain their innocence, could be so 
great; the risk of losing your job, risk, of losing custody of 
your children, your home that it is perfectly rational to plead 
guilty even when you haven't committed the crime.
    Chair Booker. All right. Chief Aguilar, it's interesting as 
an African American living in an African American community 
that's highly impacted by crime, that you have these two 
dueling reactions. One is you see how unfair the criminal 
justice system is. You know, I grew up in a predominantly white 
area, went to Stanford, Yale, saw lots of drug use, the 
enforcement of which was nil to nothing. But in communities of 
color like mine, you see a tremendous amount of drug use.
    And then on the flip side, you see all these crimes, as you 
were eloquently putting, that are going on your neighborhood 
that aren't being solved. So you have this almost double down 
discontent with your public safety, and that's a problem. 
There's one great criminal justice writer that said that black 
communities have too much of the policing they don't want, and 
not enough of the policing that they need in terms of, as we 
said, the closeout rates of murders, and shootings, and the 
like.
    But your story's extraordinary. So I'm so excited that you 
came as a witness today because you are working so hard to 
restore that trust within communities and that technology, and 
I saw this where the ACLU was dead set against me using a 
camera technology and ShotSpotters.
    We invited them in to help us write the operating 
procedures, and then how much my community wanted this 
technology being used on their streets because, like, you don't 
live here. We want cameras on our streets and the like. So I 
guess this tension that I've lived my life is something you 
struggle with every day. And technology brings a whole new era 
of challenges to something that's so important for law 
enforcement, which is police community trust.
    And so I'm hoping with that context, could you sort of tell 
me what your hope is amidst this for restoring the kind of 
trust needed for communities to be safe? And then, what is the 
excitement that you have as you see the future of this 
technology to even better help the most impacted communities 
have the kind of safety and security every community deserves?
    Mr. Aguilar. So, Senator, to your point. Absolutely. You 
know, we know that, at least through my experience, in the 
communities that are the most affected by gun violence, I have 
never heard anyone in those communities say we need less of 
this. They want everything that we can throw at the problem so 
that their children stop dying. Right. That's the overriding 
concern in the communities that are most affected by gun 
violence.
    And so what I've found is that these tools have helped us 
hone in on those people that are the drivers of repeat gun 
violence. We know through numerous studies that it's usually 
about 5 percent of our gun offenders that are driving 50 
percent of the shootings. So AI has given us the opportunity, 
along with traditional policing methods, where we employ micro 
hotspot policing, where we focus on repeat offenders.
    We saw, for example, a disturbing trend in some domestic 
homicide cases where those incidents were preceded not by 
felony incidents of domestic violence, but by misdemeanors that 
perhaps we couldn't get to quick enough. And so we found a way 
to identify those people that were repeat offenders for 
domestic violence, that we're also carrying out other crimes to 
where when we're talking about carrying out enforcement that's 
preventative in nature, we're not targeting and entire 
communities so much as we're targeting those 5 percent of the 
offenders and 5 percent of locations that drive 50 percent of 
our violent crime.
    So I think that numerous studies have also shown that the 
more police officers we have out there, the more resources, 
human resources, the more positive our impact on crime rates. 
But it goes beyond that. Right. We have to just also embrace a 
lot of these technologies that help us focus on the right 
people that are driving violence in our communities.
    Chair Booker. And technology's clearly a force multiplier. 
It allows one individual to do a lot more work a lot more 
quickly, and you've been a homicide investigator so you 
understand that. Yes?
    Mr. Aguilar. These technologies can cut out hours, even 
weeks' worth, of time in certain instances where we're talking 
video analytics, where we can get several weeks' worth of 
footage and be able to compress it to those points that are 
most relevant and of evidentiary value absolutely.
    Chair Booker. And then, how do you see--is there anything 
on the frontiers that gets you really excited about where you 
think policing might be with these tools in 5 years, 10 years 
from now?
    Mr. Aguilar. I think that a lot of the technologies, just 
like I mentioned earlier with ballistic evidence to where we 
sometimes have a hard time considering that artificial 
intelligence, a lot of these technologies are going to become 
more mainstream. We use with facial recognition as an example. 
We use it in our daily lives just to get into our phone several 
times a day.
    And so, I think that these technologies hold a great deal 
of promise. I think that they become smarter and more accurate 
with time. We just have to put behind it the responsible policy 
and the right amount of research. The NIST facial recognition 
vendor testing, for example, is an excellent resource. If we 
were to consider--if Congress were to consider Federal funding 
for some of these technologies, you know, comparing it to 
sources that are available like the NIST vendor testing, it 
would be greatly helpful.
    Chair Booker. What about training and accountability of 
police officers? I mean, my police union resisted bodycams, and 
then it shifted really quickly. They appreciated them because 
for citizen complaints, it was a very good video to have. My 
former director now thinks bodycams is great for--all that 
footage is great for training because you can break down 
officer interactions.
    I'm imagining that could be done with AI looking at the 
volumes and hours and hours looking for certain patterns that 
might help to create more accountable policing. Have you used 
it all to hold your police to higher levels of accountability 
and transparency?
    Mr. Aguilar. So, Senator, to your first point there, 
there's never enough training. And so, I am always a fan of 
more and better training. Right now, we are looking into a 
research partnership to where we will use artificial 
intelligence to go through those hours and weeks' worth of 
bodycam footage to not only highlight problematic behavior, but 
also commendable behavior.
    Chair Booker. Yes. You know, I just had a sheriff in New 
Jersey commit suicide. I have seen officer mental health 
challenges. I was just talking to a reporter about the Obama's 
21st Century Task Force on Policing, and they saw a lot of 
predictive analytics for officer misconduct. One of them, which 
is actually doing suicide calls, seemed to be something that 
would pop up before an officer would have an interaction with a 
citizen that was negative. And I don't know if that's something 
you're thinking about how to see how AI might be able to help 
in that space to anticipate officer behavior who might need 
more training.
    Mr. Aguilar. Without a doubt, Senator. I think that any 
technology that'll help us flag problematic behavior--we've 
seen it. We've seen officers whose careers have come to a very 
ugly end, right, and they're often proceeded by problematic 
behavior where that officer could have benefited by from early 
intervention. And so, we as a police department can't correct 
problematic behavior that we're not aware of. And so, if this 
technology helps us get there, I'm all for it absolutely.
    Chair Booker. And so I would imagine--and I'm just on the 
last question then I'd like to move on to Dr. Howard. I do hear 
this though still in my community. My young kids are stopped 
and frisked more than any other community. This doesn't happen 
in wealthier, whiter communities. Now we're under video 
surveillance in ways that other communities are not. Now they 
have facial recognition that we're exposed to more than other 
communities. You can see how that list can go on, and on, and 
on, and on, which I wonder if people start to feel like they're 
under a surveillance state, or feel like they're having their 
just basic privacies. Could you empathize with that feeling, or 
is that just not your experience that you're seeing out there 
at all?
    Mr. Aguilar. So, Senator, I think that right now, video 
cameras are ubiquitous. I read in one place, I can't remember 
the exact source, but the United States is second only to China 
in terms of the number of video cameras that the average 
citizen encounters every day. The difference of course, being 
that most of the video cameras that we as Americans encounter 
are owned by individuals, are owned by the private sector.
    And so I think that perhaps in some communities that are 
more prone to gun violence, where some of the cameras belong to 
law enforcement versus other communities where they're held by 
individuals in the private sector. But I do think that right 
now, being under some form of camera surveillance is just an 
accepted part of life for all communities throughout the United 
States.
    Chair Booker. Thank you. Dr. Howard, I was really 
appreciative of your sort of best practices, and they resonated 
with Dr. Wexler in a significant way. And one of the things I 
think that resonates with Chief Aguilar is just this idea of 
training. Could you just go another level deeper on that? You 
said how important it's for analyst training. What does that 
mean?
    Dr. Howard. So we know that in order for these tools to be 
used properly, the analyst decisions before the algorithm comes 
into play, are critical, and the analyst decisions afterwards. 
So if we think about any one of these, if we think about a 
latent print analysis, for example, just to use a different 
one, the analyst, somebody in the human chain collects a 
fingerprint at a crime scene, or from a piece of evidence 
processes that fingerprint scans it.
    It decides whether it's of sufficient quality to even be 
able to match it to something else, or to attempt to link it to 
somebody else, marks it up, or has a computer program mark it 
up on where the key features of this fingerprint that might be 
worth comparing with a data base, puts it into the algorithm. 
All the algorithm is doing is comparing it to a data base of 
prints.
    There's nothing magical about that. That's been done for 
decades on computers before that, on cards stored in files. 
They would pull out the cards and they would compare each 
fingerprint. So all the algorithm is doing is speeding up that 
comparison process. And then at the end, it puts out a 
candidate list, and that candidate list is nothing more than 
the top 10, 20, 50, however many the program is designed for, 
or however many the analyst has asked for of the best matching 
candidates from the, you know, the best match at the top to the 
lesser matches as you move down the list.
    But that doesn't say anything about the strength of the 
actual evidence. The person at the top of the list might 
actually be a lousy match, but it's the best match in the data 
base, and that's all the algorithm is able to do. If you have a 
partial print, or a smeared print, or one that's distorted, 
they may not be able to get a very good match. And if you were 
putting a percent match on it, which is not what these 
algorithms do, but if you were doing that, it might say 
something like 35 percent match, and that's your number one 
candidate.
    Analysts often do not understand that. They often think 
this is my number one candidate, or these are my top 10. It's 
got to be one of these people that came up at the top of the 
list, and in reality, it might be somebody completely 
different. All the algorithm can do is find the best matches to 
whatever quality fingerprint they're given, and it has to be 
somebody who's already in the data base. And obviously, not 
everybody has their fingerprints in every data base that could 
be used for comparison. So a lot of human understanding at the 
beginning about what quality of print is good enough, and human 
understanding at the end about what do these results really 
mean.
    Chair Booker. Right. But variations in training for local 
police departments could vary widely and end up with widely 
different results.
    Dr. Howard. That's absolutely true.
    Chair Booker. And so that's why one of your recommendations 
is to have national standards. Right?
    Dr. Howard. We think national standards would help to drive 
the conversation if there were standards at the Federal level, 
or if there were standards that applied to how much is good 
enough. Right? What quality of print is good enough to put into 
a latent print algorithm?
    Some of those kinds of standards could start to bring more 
consistency to this and help reduce the potential for well-
meaning human investigators who are doing their best to solve a 
crime, to be able to use the tools more effectively and 
interpret the results more efficiently.
    Chair Booker. Right. And how would you feel, is that overly 
prescriptive for the Federal Government? Because I'm a big 
believer having run a local police department, how cash 
strapped you are, how you're constantly battling for resources. 
And so things like cops grants and other grants for technology 
are really critical. But how would you feel if those grants 
came with a requirement for certain standards for your analysts 
and the like? Is that overly burdensome?
    Mr. Aguilar. Senator, I think that, you know, it's a bit of 
a broad question. But I think that just generally speaking, a 
grant that comes with a requirement that the agency receiving 
the grant properly train to a particular standard the people 
who are going to be carrying out the function, I don't think is 
overly burdensome.
    Chair Booker. Great. And so Dr. Howard, last question. When 
you say increased transparency, are you getting at some of the 
things that Professor Wexler's talking about in terms of the 
need of opening up these algorithms to peer review and to sort 
of a more adversarial analysis?
    Dr. Howard. So we looked at the criminal investigation 
portion, which I realize feeds into the courtroom, but we did 
not look at the courtroom processes that might occur. So I want 
to set the stage with that. But the experts we spoke with 
indicated that transparency is critical, both in terms of how 
the algorithm was built, what if it's an AI-enabled algorithm, 
what training data were used, but also then transparency about 
has it been tested. What is the accuracy of this through 
something like the NIST facial recognition vendor testing? What 
accuracy was determined through that kind of testing? What 
demographic bias did this algorithm exhibit through that kind 
of testing? That can be very useful information, and our 
experts were very much in favor of that.
    Opening the source code, though our experts told us it is 
not necessary. It is a path to figuring out how the algorithm 
works. It is not the only path in the view of the experts we 
spoke with. Independent third-party testing can accomplish many 
of the same things.
    Chair Booker. And you guys noted in your report that there 
was a lack of sufficient independent validation.
    Dr. Howard. That is often true. Yes. The NIST tests which 
are top of the line, gold standard testing, they are done only 
if a vendor chooses to submit its algorithm for testing. 
There's no requirement for a vendor to do that.
    Chair Booker. And you're saying right now the DOJ, there's 
a lack--in the DOJ's engagement of this technology right now, 
there's a lack of sufficient independent sort of oversight.
    Dr. Howard. So we didn't look at the DOJ in depth in terms 
of how they validate their algorithms. We did talk to a number 
of officials at FBI, and they told us--and I believe this is in 
our report--that they worked with NIST to develop a validation 
protocol that they then run in-house.
    Chair Booker. But you haven't evaluated that.
    Dr. Howard. We have not evaluated it, no. That was not part 
of the scope of our work. It's work we could do if there was 
interest.
    Chair Booker. Well, I have interest, but I can't speak for 
the DOJ. But if you were to be called upon to do that analysis, 
one of the things you would be looking at is sort of an 
independent objective review, a sufficient review of algorithms 
of the technology itself. Correct?
    Dr. Howard. Of the algorithm accuracy, demographic bias, 
features like that.
    Chair Booker. And what's the danger of perhaps them not 
having done that right now?
    Dr. Howard. Then they may not know how effectively their 
algorithm works, and they may not know that the candidate list 
they get out could be skewed by, for example, bias-training 
data that the algorithm was trained on. They just may not be 
aware of that if they haven't run that test.
    Chair Booker. Doesn't that set alarms? Should I be writing 
to the DOJ and saying, ``Look, I have legitimate concerns that 
you have not tested this in a sufficient way.''
    Dr. Howard. I would say any law enforcement entity that's 
using an algorithm that has not been validated in a form that 
would be considered defensible should set off alarms. 
Absolutely.
    Chair Booker. Okay. And then finally, Ms. Wexler, again, 
you traveled the farthest and I'm grateful. But I do wonder, 
you obviously have a lot of concerns in your testimony, but 
there are also protections that AI tools could use. I always 
think of these waves of technology as potentially democratizing 
because you talked about the possible expense of a defense 
attorney in a situation, but AI might be a tool that defense 
attorneys could use to help out.
    You've done a lot of writing and obviously sit with the 
technology group at Boalt. Are there some things that give you 
hope when you look at this technology that you might want to 
put into the record?
    Professor Wexler. Oh, yes, absolutely. To be clear, my 
concerns are neutral about the technology itself. I think AI 
technology is have potential to increase accuracy and efficacy 
of law enforcement investigations and prosecutions, and also 
have the potential to help criminal defense investigators 
identify evidence of innocence.
    So the technologies themselves are not the issue. It's the 
legal rules that we set up around them to help us ensure that 
they are the best, most accurate, and effective tools, and not 
flawed or fraudulent in some way.
    Chair Booker. I just want to say before I give my sort of 
closing remarks. Number one, I'm just so grateful to Senator 
Cotton with a lot of demands given some of the international 
issues that are going on for him to be here and give such, I 
thought, a really important line of questioning. His 
partnership is extraordinary.
    But I want to thank the three witnesses. It is a frontier 
that we have that I think it's difficult to anticipate where we 
will be in 5 years from now, and this technology is really 
accelerating.
    The challenge for government, and I've seen this in waves 
of innovation, is that we have not moved as fast as the 
innovations around us. I've seen this in nuclear energy. I've 
seen this in drone technology. The government has not been able 
to keep up. Maybe a platform of the substantive accord that we 
have in a bipartisan way on some of the challenges with social 
media, for example, is another great example.
    You-all are on the cutting edge of looking at this. And 
it's exciting to me not only to hear your testimony, but to 
hear what some common-sense precautions could be on a federal 
level, as well as ways to try to figure out how to advance the 
technology to the greatest aims of humanity, which is a 
democratic system that protects the rights of all individuals, 
including rights to privacy, as well as what I think is a 
fundamental human right or a freedom that we should have; which 
is a freedom from fear, a freedom from the kind of depraved 
criminality that we often see manifesting in communities as 
well.
    This testimony's been rich, both your written testimony and 
your verbal testimony. It gives me a lot of gratitude. I know 
that Congress as a whole is looking at AI from every different 
perspective. This is, from what I know of, the first hearing in 
the Senate that really is focusing in on. It's affecting the 
criminal justice system.
    My hope is that you-all will be available in the future to 
consulting with us. There may be some potential for some great 
bipartisan ideas to come out of this, or at the very least, 
opening up conversations with some of the key actors in law 
enforcement on the federal level. I cannot tell you, Chief 
Aguilar, as a guy who lives in a community that has struggled 
with a lot of the issues that yours has, the heroic work that 
you're doing every single day. It's just something that means a 
lot to me, and I look forward to visiting it hopefully. And the 
truth of the matter is I'm a little concerned that we'll be 
confused for each other because we're both--you know, have 
similar haircuts. But I'm hoping that that won't be the case.
    But I want to remind everyone that the Subcommittee 
questions for the record are due a week from today, Wednesday, 
January 31 at 5:30 p.m., and I hope that, should there be 
questions, because again, the Senators have been pulled in so 
many different directions. My Ranking Member's team might have 
some questions for the record as well. I hope that you-all 
after all the sacrifice you made, getting here, preparing 
written testimony, and testifying, that you will still be able 
to respond in a timely fashion to any questions that are sent 
to you.
    When you testify before the U.S. Senate, I know how 
important that is. It may seem like a small Subcommittee 
hearing, but it is a service to your country, and the work that 
you-all are doing to me stands in that stead of patriotism, of 
giving to a nation, helping us to be better. Today was very, 
very helpful, and I'm grateful to each of you individually for 
participating and being a part. With that, the Subcommittee is 
adjourned.
    [Whereupon, at 4:02 p.m., the hearing was adjourned.]
    [Additional material submitted for the record follows.]

                            A P P E N D I X

Submitted by Senator Booker:

 CAIDP--AI and Criminal Prosecution Statement.....................    65
 
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

                                 [all]