Better Juries through Science

By Sheeva Azma

Making a trial an educational experience helps non-expert fact-finders grapple with scientific evidence.

Because I belong to the National Association of Science Writers, I was lucky enough to virtually attend a two-day conference on science and the courts, happening September 21 and 22, 2023, for free. I was only able to attend the first day, but I learned a lot – read all my session recaps here.

While the earlier sessions on this first day focused on judges and court systems, this session, titled “In the Minds of the Jury,” focused on improving, evaluation, and understanding of evidence by jurors, judges, and witnesses. A primary focus of the discussion was juries and how their minds perceive evidence and make decisions. Caroline Montojo, who leads the Dana Foundation, moderated the discussion.

Juries have the difficult job of recalling, understanding, and evaluating information in pursuit of justice. That’s why studying the neuroscience of juries can help understand the ways jurors minds might absorb or reject court evidence presented to them. The panelists discussed the neuroscience and psychology of deliberation, as well as tools that could be used to help jurors do their job better.

One takeaway I got from this session was that juries actually do a decent job of deliberation, even when scientific evidence is involved. Learning this just reinforced, for me, the idea that many minds, put together, can solve difficult challenges.

Solution #1: Educate Juries on the Neuroscience of Memory

The first speaker was Dr. Emily Murphy, a law professor at the University of California-San Francisco College of Law. She started her talk about eyewitness testimony and its reliability (and unreliability) with a slide that showed how the public thinks about memory, compared to how experts, such as neuroscientists, understand it.

Over 50% of the general public stated that they agree with the idea that human memory works like a video camera, recording events accurately, while no experts agreed with this statement. As a neuroscientist, I know that human memory is not always reliable. It can be fragmented, and the facts and circumstances surrounding an event are not always correctly remembered. (When I was in grad school, one of my professors joked that if we could really remember every single thing that happened to us as people, our brains would need to be a lot larger to hold all that information.)

Therefore, some of the work of helping juries make good decisions is helping them understand how memory works. This plays a role in things like eyewitness testimony, where witnesses try to recall an event and testify regarding their recollection in the courtroom. The facts may not always be correct, even if the witness feels confident in the reliability of their memory, and the memory may change over time. Psychologists and neuroscientists have known about this and studied it for years, but as Dr. Murphy stated, “this is just not something that the general public, who sit on our juries, understand.”

Autobiographical memory is a type of memory that involves things that have happened to someone. Witnesses in a trial may be asked to testify about things that happened to them, and their memories of events. In other words, the witnesses provide evidence in the form of their autobiographical memories. Dr. Murphy recounts investigations into the molecular basis of memory which state that every time a memory is accessed, that makes it “labile”: prone to changes, and thereby, prone to distortions.

If the public thought about autobiographical memory, they might have different views of the court room and legal process. Dr. Murphy suggests one way to improve juries’ deliberation and decisionmaking: to train juries on the neuroscience of memory. Explaining to jurors that autobiographical memory is not fixed and not stable can help them evaluate autobiographical memory testimony better.

The bottom line here is that training jurors to be more savvy about how memory works and what it can and can’t do can help improve the justice system. Explaining frameworks for understanding evidence to jurors and judges helps them understand these shortcomings about the nature of evidence. Training juries in this way would increase reliance on documentary evidence, and decrease reliance on testimony.

Solution #2: Recognize “Loose Gatekeeping” as an Unintended Barrier to Justice

The next speaker was Dr. Michael J. Saks, a law professor at the Arizona State University’s Sandra Day O’Connor’s College of Law. He talked about the challenge jurors face in evaluating facts about things where they are not experts. The judge acts as a gatekeeper of scientific evidence; what they admit as evidence in the courtroom becomes the information (accurate or not) that makes up the judicial discourse for that particular case. The intended effect of this was to prevent false and misleading information from being presented to jurors, but there’s also an unintended effect.

When people lack knowledge to solve a problem, they rely on superficial indications of what the correct answer might be. Therefore, when the judges admit evidence that is on scientifically shaky ground, jurors may not know that, so they will give more weight to the evidence than it deserves. Dr. Saks discussed research which has shown that when the judicial setting serves up shaky evidence, jurors give inordinate credit to that evidence, even though it has flaws.

This creates problems. If a judge accepts unreliable evidence, a lawyer on the other side may exploit this. Lawyers may introduce evidence that is unreliable, such as microscopic hair analysis, claiming that the facts speak for themselves, and even overstating the findings to make claims that are not supported by science. Bullet lead analysis, fingerprint analysis, and other types of forensic evidence are often admitted, but they are by no means foolproof or in many cases even validated. Given that the legal system is an adversarial one, this “loophole,” resulting from a lack of science literacy, can be used to falsely convict people. “Testify first for 10, 20, 50 years, and validate later,” says Dr. Saks of the problem.

Many solutions have been proposed, including in a 1901 Harvard Law Review article by Learned Hand; 1991 Wisconsin Law Review article; and 2022 Vanderbilt Law Review article, but none of the solutions have been put into practice.

“The law should help juries do the best job they can,” Dr. Saks concluded.

Solution #3: Make Trials as Educational as Possible

The next speaker was Dr. Valerie P. Hans, a law professor at Cornell Law School, who discussed the use of social science in law. She studies citizen participation in legal decision-making in other countries. With Dr. Saks, she has published an article with concrete recommendations to improve judge and jury evaluation of scientific evidence.

These recommendations include maximizing understanding in the expert evidence presentation and even overall trial structure; promoting understanding in trial procedure reforms; educating judges and juries; and ensuring that juries are diverse and deliberations are robust.

Dr. Hans encouraged more deliberative, thoughtful approaches to juries’ decisionmaking. She suggested that judges and lawyers should help juries think more systematically and rationally, rather than emotionally. Diversity helps juries make more just decisions, and achieving a diverse group of people is easier for larger juries (12-person versus 6-person juries, for instance).

Making the trial more educational can help ensure a just conclusion by empowering juries with knowledge they need for sound decisionmaking. Scientific evidence should be presented to maximize comprehension, so scientific information should be presented in as educational a manner as possible.

Lastly, Dr. Hans talked about deliberation. Scientific evidence can be discussed in deliberation. As Dr. Hans stated, taking math and science courses is linked to scientific understanding in juries. She recounted an example of a case involving mitochondrial DNA evidence, in which deliberation boosted juror comprehension of evidence.

Juries generally do a good job, Dr. Hans stated, even in complex cases, with some help from lawyers and judges. Many juries are diverse, engage in robust deliberation, and discuss the scientific evidence.

During the question and answer period, Rick Lempert, a member of the audience, pointed out that juries don’t have to understand the evidence like an expert would; they only need to understand it to use it in the case.

Lastly, figuring out the questions jurors might have and answering them can help improve scientific understanding. Trials can allow jurors to ask questions in limited circumstances, which also helps to manage some of the traditional roles of the lawyers, the ones who are involved in questioning.

Learn More about Science’s Role in Justice

If you want to read my blog recaps of the other sessions I attended at this conference, check them out here. You can also watch this session and the whole conference on YouTube.