Arturo Casadevall has zero training in forensic science—the techniques used in law enforcement and the courtroom to link individuals to crimes. For most of his career, the microbiologist at Johns Hopkins University in Baltimore, Maryland, paid the discipline little attention, but he did notice the field-shaking 2009 report from the National Academy of Sciences (NAS), which found that many forensic techniques, from fingerprint comparisons to bloodstain pattern analysis, lacked a firm scientific footing. “I remember reading [NAS] about this and I said, ‘Oh my God, I thought fingerprints had been validated,’” he remembers.
He would soon play a direct role in the field’s reform, as one of a handful of basic researchers invited to serve alongside lawyers, judges, and forensic practitioners on a panel, created by the U.S. Department of Justice (DOJ), in partnership with the National Institute of Standards and Technology, to advise DOJ on how to respond to the NAS report’s concerns. Since its founding in 2013, the panel has published 43 documents and made 20 official recommendations to the attorney general, including a call for the universal accreditation of forensic practitioners and for the phasing out of the meaningless phrase “reasonable scientific certainty” that is common in courtrooms.
Last week, Casadevall and five other scientific members of the commission wrote a letter to Attorney General Jeff Sessions and acting National Institute of Standards and Technology Director Kent Rochford asking them to renew the group’s charter, set to run out 23 April. Instead, Sessions and DOJ announced on Monday that the charter would be allowed to expire, and he requested proposals for a new advisory committee or an office within DOJ that would advance forensic science—a move many fear will exclude mainstream scientific views from future policy decisions.
Casadevall spoke to ScienceInsider about the commission’s value, its limitations, and what he expects to be its legacy.
Q: What was the logic behind this panel?
A: If you think about it, the techniques that formed forensic science were created to try to do criminal investigations. … Their ancestry is out of the mainstream of science, in the sense that they were developed for the purpose of trying to help solve crimes, and consequently, many of these techniques never got validated. … The big innovation of the commission was that you had mainstream scientists sitting at the table with judges, prosecutors, and forensic [practitioners]. … We [scientists] were there because science has traditions and approaches that transcend disciplines. Even though our domains are very different, our approaches to inquiry, our approaches to error, are pretty similar.
The first five meetings of the commission, very little got done because we were trying even to learn to talk to one another. We come from completely different worlds. Law works as a dichotomy—you’re guilty or not guilty. In science, all knowledge is provisional. I assume that what we’re doing in my lab today is going to be overturned in the future.
Q: What do you see as the key products of the commission?
A: I think the document that was voted on in September  stating that new techniques of forensic science need to be independently validated is a really important line in the sand. … Today, if you develop a new technique to characterize white powders, and you start a company, you can actually sell this to police departments without necessarily going through any [validation] mechanism … and then use it in court, in a situation in which the lawyers don’t know any of the science. So who is going to challenge any of this?
The recommendation was that it should go to an independent entity that is not part of the justice department. … And to me, that is probably the single most important output of the committee. That at least is on record.
Q: What about all the existing techniques that are still used in court and haven’t been validated, such as bite mark evidence?
A: Of course, we wanted [the document] to be bigger. We wanted it to be retrospective. But we had to compromise to get the votes. … We were a deliberative body and we need to get a product out, and if you dig your heels and say all of it needs to be independently validated, you couldn’t even get that statement.
You can’t put the genie back in the bottle. The questions are out there. The Innocence Project, for example, is training lawyers on what questions to ask [about certain] techniques. We have an adversarial system. Inevitably, the pressure is going to come in, even from the prosecutors who say, “Hey guys, we’ve got to fix these techniques, because every time I present this, they hit me with these questions.” … There is a greater awareness now that if you’re going to introduce any of these things into court, you may be asked, “Where is your error rate? How do you really know what a match is? What does that mean?” I tend to look at this as progress.
On Monday [at the commission’s final meeting], there were two documents that were voted down. … One of the documents was just to recommend that when somebody testified, if you asked them about an error rate, they should be able to tell you that they had it, or that they didn’t know. I think that if I stopped somebody on the street and I asked them, most people would agree that this is a reasonable thing. But some of the people … felt that this recommendation would be used by defense lawyers to question a lot of [forensic] practitioners. If we had continued to meet, those documents would have gone back to committee … and they would have figured out a way to work around … and they may have passed in the summer meeting or the fall meeting.
Q: Did you expect the commission’s charter to be renewed?
A: The truth of the matter is we did not know. We knew it was a congressional charter and Congress had basically appropriated money to run the commission a certain number of cycles. We thought that with the new administration, there was a high probability that perhaps it didn’t get renewed.
Q: Why wouldn’t DOJ support continuing the commission?
A: Sessions’s statement doesn’t say anything bad about science. They basically say that we’re going to take this and we’re going to put it back in the Department of Justice, create a new office of forensic science. On the surface, that sounds good. You could imagine that they could create an office with a lot of scientific input. … The problem of forensic science is that it grew out of an arm of the judiciary, and by putting it back, you basically don’t deal with the questions that are being asked from mainstream science. … The commission was the only mechanism that existed where you had working scientists talking to people who actually do forensic science to generate data that is consumed by the legal system. And we were a minority.
I served on the anthrax investigation—the National Academy of Sciences study that was done on [the 2001 anthrax mailings]—so I can tell you that the culture of criminal justice feels very uncomfortable when you question their techniques. And that is natural. These people are trying to reduce crime by putting people away. And here you have a situation in which techniques that they have used for many, many years come into question, and I think there is natural instinct to say, “Oh, God.” Some of that may have been there. But there are also a lot of people who recognize that these problems aren’t going away. And the way to deal with this is to do the science.