Mimesis Law
6 July 2022

Mark Perlin, The Man Inside The Black Box

Nov. 30, 2015 (Mimesis Law) — Dr. Mark Perlin, Ph. D., M.D., Ph. D., has built a better mousetrap. At least, he says he has. As to whether his trap is actually better at catching mice, or whether it’s actually catching mice at all, well, we’ll just have to take his word for it.

Dr. Perlin (or is it Dr. Dr. Dr. Perlin?) founded a company called Cybergenetics. Cybergenetics developed software called TrueAllele Casework, which is a computer program that “rapidly infers genetic profiles from all types of DNA evidence samples.” So far, so good. The problem is, Cybergenetics has refused to release the source code of TrueAllele, claiming it’s a trade secret. In California, at least, an appellate court has signed off on the refusal, holding that:

[The defendant] has received extensive information regarding TrueAllele’s methodology and underlying assumptions, but he has not demonstrated how TrueAllele’s source code is necessary to his ability to test the reliability of its results. We therefore conclude that Chubbs has not made a prima facie showing of the particularized need for TrueAllele’s source code.

The court is missing the point. The defendant can’t examine the source until he can show why he needs it for his defense, but he can’t show what, if anything, in the source code he needs for his defense until he (more specifically, the expert hired by his attorney) examines it. It’s like being given a description of what an automobile does without being able to open up the hood and poke around.

Cybergenetics’ refusal to release the source is because of the “highly competitive commercial environment” of DNA software. This makes some kind of sense. Crime labs around the country pay upwards of $60,000 to license TrueAllele. If the source code could just be downloaded, cheap imitations could cut into their profit margin.

Let’s leave aside the question of whether or not Cybergenetics profit margin trumps a defendant’s rights to due process. Cybergenetics concern is overblown. No attorney is ever going to read TrueAllele’s 170,000 lines of source code into a public record. The only person who is going to review that code and make sense of it is the defense expert. Any testimony relating to it would have to be at a level that a jury (or a judge) could understand, which won’t be enough for a competitor to reverse engineer it. A judge could order that a copy be provided to the defense’s expert, and not be disclosed to anyone else.

Dr. Perlin contends that the source code is unnecessary. Instead, he suggests that all that matters are the “peer-reviewed, scientifically validated” tests of the software. Essentially, he says that when the software is fed test cases, it comes up with the right answer. However, of the validation studies listed at the Cybergenetics website, Dr. Perlin is listed as an author on three of them, and the primary author of another works for the Virginia Department of Forensic Sciences. For a defense attorney, that’s not good enough.

Presumably, prosecutors would prefer that we were all as blown away by Dr. Perlin’s virtuosity as this reporter:

It was so powerful that Wakefield’s defense attorney, Fred Rench, who for months was calling Perlin’s science “voodoo,” quickly abandoned that strategy. Perlin, who has a medical degree and doctoral degrees in computer science and mathematics, was an 800-pound brain in the room. As the saying goes, Rench could not stop him, he could only hope to contain him.

“After consulting with multiple experts, it was a strategically better approach to adopt the DNA due to the deficiencies in the proof when one considered all of the DNA evidence,” Rench told Law Beat after the verdict.

Perlin has a patent on his technology. Only he and one of his colleagues know the “source code” behind it.           

Reduced to its essentials, Perlin testified “It’s a match. The machine says so!” But when the defense wants to find out how the machine works, the answer is, “It’s a secret!”  I’m not suggesting Dr. Perlin is dishonest. But, like everyone else, he’s not infallible. The nature of criminal defense is that an attorney must be ready to find and pursue any line of defense, no matter how remote or abstract, and be able to subject any aspect of the prosecution’s case to, in Justice Scalia’s expressive phrase, “the crucible of cross-examination.”

Dr. Perlin and Cybergenetics may be acting with all the good will in the world. There is no indication that he is the Annie Dookhan of DNA. In fact, he doesn’t appear to be simply a shill for prosecutors, since he’s done work with the Innocence Project. Here’s what one of his colleagues there had to say about TrueAllele:

Greg Hampikian, a biology professor at Boise State University who worked with Mr. Perlin on a wrongful conviction case, said he is less concerned about TrueAllele’s source code than its performance in double-blind and peer-reviewed validation studies.

“The proof is in the pudding—not the recipe,” said Mr. Hampikian, who is director of the Idaho Innocence Project, a nonprofit legal group that pursues exonerations.

With all due respect to Professor Hampikian, that’s a biologist talking, not a lawyer. When I’m defending a case, I might need the pudding, the recipe, the pots, the pans, the cooks’ names, and anything and everything else. Because the proof might be in the pudding, but reasonable doubt is wherever you find it.

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