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Opinion How do we reconcile law and science?

Symbol of law and justice in the empty courtroom, law and justice concept. (iStock)

Note: This is the third of a six-part online symposium on the use of forensics in the criminal justice system. You can read the introduction and part one here, part two here and the full biographies of the panel here.

Question 3

There seems to be an inescapable tension between the fields of law and science. Law strives for consistency and finality, so courts tend to look to precedents for guidance. Science is always changing with new evidence and new research. But of course science is an important tool in the search for justice. We’ve also entered the era of “alternative facts,” in which the courts pick and choose between expert testimony that’s not only contradictory, but also irreconcilable. Several media outlets have documented a disturbingly large and growing number of court rulings that have relied on expert testimony and assertions in amicus briefs that are flat-out wrong.

How do we ensure that the justice system operates on reliable information? Are there other systems in other parts of the world that do a better job at this? Is it even possible to “fact check” our courts in a way that enforces accountability, or are we simply stuck hoping that appeals court judges will admit and correct their mistakes?

Simon Cole, Department of Criminology, Law & Society, University of California at Irvine; National Registry of Exonerations:

I think it is less a fundamental incompatibility between law and science as it is outcome orientation. Judges want the prosecution to win. [My student] Rachel Dioso-Villa published a study that found that judges are far more critical of arson science in civil cases, when it is often proffered by plaintiffs, than in the criminal cases, when it is usually proffered by the government. There are other studies with similar findings.

John Lentini, fire/arson expert:

We can do that by removing some of the constraints of the legal system. Several states (Texas, California, Connecticut, Wyoming and Michigan) have instituted new rules to allow for appeals even after all of the deadlines have passed, if it can be shown that the science underlying an expert’s opinion that was used to obtain the conviction has changed. Texas has even allowed appeals to take place when the expert changes his or her opinion as a result of gaining more experience. Every state should have such rules. Recently, Virginia very unwisely decided it was too expensive to implement this removal of constraints, which just tells me that they need to be hit with a few more multimillion-dollar judgments for wrongful convictions before they get their minds right.

Sandra Guerra Thompson, University of Houston Law School, Houston Forensic Science Center:

Texas and a few other states now have a “junk science writ” that allows people who were convicted based on flawed science to have their cases reviewed by appellate courts. Texas has also created a uniquely influential Forensic Science Commission that in 2016 effectively rendered one type of junk science — bite-mark evidence — inadmissible. These new developments create judicial awareness about forensic disciplines that have proven to be unreliable. This awareness, in turn, should make trial judges more willing to revisit past precedents when considering whether to admit forensic evidence in the face of a well-reasoned defense objection. The law, like science, does evolve and change.

Frederic Whitehurst, FBI crime lab whistleblower, Forensic Justice Project:

First, we need to recognize that our inability to handle this disharmony has resulted in human rights violations. Individuals are now being freed after decades in prison for crimes they did not commit because their convictions were based on, for instance, forensic hair analysis. These are human rights violations. Once we've called the situation what it is, we can begin to find ways to reconcile these two fields.
As a PhD candidate in the 1970s at Duke University, I found myself in a chemistry research building across the street from Duke Law School. Neither future lawyers nor future scientists ever crossed that street. With all the talent at Duke, no one crossed the street to tackle some of the most complex and exciting scientific and legal issues of our day.
Nationally, some have finally have crossed that figurative street. A forensic science commission comprised of scientists and lawyers, commissioned by the White House, was leading us in the right direction. They were then abruptly shut down on the mere whim of the lead attorney in this country, our own attorney general. Next time, we should put this in the hands of the people, through their representatives, and not in the hands of the executive branch.

Itiel Dror, University College London, Cognitive Consultants International:

The problem, I fear, is worse than even this. The nature of the adversarial legal system often means that science is not used to administer fair justice, but is abused and misused in court, by both sides, fighting from their corners. The adversarial system is not only not scientific, but is in many ways anti-scientific.

Jules Epstein, Temple Beasley School of Law, National Commission on Forensic Science:

I am not sure that this is at the root of “most” of the problems, but it has a large impact. The remedy here is to moderate the criminal justice system’s preference for finality with appropriate options for revisiting cases when new science has shown a flaw in the prior proceeding(s).

Barbara Spellman, University of Virginia School of Law:

I think that these characterizations of law and science, although partly accurate, are caricatures of them. Law and science do have very different methods and some different goals, but also some similar goals — like getting to the truth. Each also wants consistency: law in application of the rules (e.g., treat like cases alike) and science in the value of parsimony (e.g., scientific laws should be generalizable without ad hoc exceptions). When inconsistencies arise in science, they may get explained away (e.g., noting that a study’s methods were bad or not applicable to a particular question), forgotten completely, or put away into a file of troubling results that may, sooner or later, with other results and supporting theory, be used to overturn previous beliefs. Thus, while science does adapt and change, it isn’t necessarily very quickly.
Law has some analogous methods. What counts as precedent is in the eye of the beholder; judges can “distinguish” earlier cases and say “that decision is not applicable to this case.” Appellate courts do this all the time when dealing with previous law. In fact, this exercise — understanding what factors of a case may be relevant to a subsequent case — is a foundation of law school training (e.g., for subjects such as contracts, torts, constitutional law, and, of course, evidence law). When the interpretation of an earlier case becomes so riddled with “exceptions” and so inconsistent with later cases that have found ways to distinguish it, they may be entirely overruled and replaced with cases that determine the important factors for deciding.
I don’t know why judges don’t prevent the use of bad forensics more often. But a big difference between law and science is that in law a decision has to be made, by one person (or, in an appeal, a small number of people), within a very short period of time, with consequences to a particular person. It may be difficult to go against previous norms under those circumstances. In science, belief change happens by growing discussion, accretion of information, across the community, and over time.

Roger Koppl, Forensic and National Security Sciences Institute, Syracuse University:

I don’t think there is all that much to reconcile. In both cases you have evidence that is subject to multiple interpretations. And in both cases you just can’t eliminate all doubt. It seems like science and law operate on opposite principles only when we ask science to give us the one true interpretation of evidence that, in truth, can be interpreted in more than one way. If we had a real and substantive defense right to expertise, this multiplicity of scientific interpretations would be more obvious. And that would be a good lesson for the judge or jury!

Keith Findley, Center for Integrity in Forensic Science, University of Wisconsin Law School:

As the law increasingly relies upon science as a foundation for its judgments, the law will have to adapt to the nature of scientific knowledge. As noted, the law generally demands certainty and finality. But science is always evolving, contingent, never final. To the extent that legal judgments rely upon scientific evidence — that is, especially in those cases where scientific evidence provides key parts of the case used to convict — the law must be willing to abandon finality when that scientific evidence shifts. That is to say, if the foundation of a case is built on scientific evidence, and that foundation shifts in meaningful ways, the law must close what Professor Jennifer Laurin at the University of Texas calls the “science lag” in the law.
Fortunately, some state legislatures are beginning to recognize the need for law to adapt to science. Texas, California and, to some degree, a few other states have now passed laws allowing courts to reopen old convictions that rested upon outdated science.

Judy Melinek, forensic pathologist, author of “Working Stiff: Two Years, 262 Bodies, and the Making of a Medical Examiner”:

Law and justice are not the same thing. Law might strive for consistency and finality, but all of us who work within the criminal justice system must seek its fair and just application. Justice requires empathy, transparency and the ability to correct error. If the courts are following the laws placed before them by legislators, then it’s time to find legislators who are serious about criminal justice reform and who are ready to pass laws that fund forensic labs and require the legal system to give the wrongfully convicted a second chance at overturning their unjust convictions — and at seeking retribution.

Roderick Kennedy, retired judge, New Mexico Court of Appeals:

We cannot do our work in the justice system without using science to explain the significance of evidence that cannot be explained, save by the application of specialized knowledge and expertise.
Judges need better education, as do lawyers. Hence, I’m teaching scientific evidence/expert testimony at the University of New Mexico law school. Science can give lawyers the gift of baselines from which to measure forms of truth. The idea of calibrating a thermocouple at .005 degrees Kelvin is no different than the idea and reason for calibrating a breath test machine, nor is the method for doing it. Gauging uncertainty of measurements has been a bête noire in DWI testing, but lab certification standards require it — to much noncompliance and prevarication. That’s an example of a sort of universal idea that isn’t hard for a lawyer or judge to grasp.
The next step is for judges to insist that such standards be employed. The [National Academy of Sciences] report and the [President’s Council of Advisors on Science and Technology] report, to give two examples, were scientific reports that were critical of the legal profession in ways that are absolutely true, then and now, but that also provide models for education. I attended a judicial science week at Los Alamos National Laboratory with Justice Barbara Hervey from the Texas Court of Criminal Appeals. Read her opinion in the Steven Mark Chaney bite mark case, and you’ll see how a conscientious judge can put these ideas into practice.

Read more from Radley Balko:

Part 1 of this series: We need to fix forensics. But how?

Part 2 of this series: How much should juries rely on expert testimony?

Part 4 of this series: Is an adversarial justice system compatible with good science?

Part 5 of this series: How much interaction should we allow between forensics analysts and law enforcement?

Part 6 of this series: How do we improve forensics?

In this Louisiana courtroom, statistically improbable jury pools give prosecutors an advantage

Journalists need to stop enabling junk forensics