Prez advisors warn: halt convictions based on pseudoscience


Galileo tries to persuade the Inquisition to look at the Moon through a telescope.

A mysterious Deep Throat, known only as Dr4ensic, has leaked a draft report from a Presidential commission warning that courts are falling down on their job of keeping out junk science offered by the prosecution.  That’s mighty public-spirited of Dr4ensic, considering that the report trashes his own field of bitemark comparison, among others, as  hopelessly unscientific. Yup, the President’s Council of Advisors on Science and Technology (PCAST) has concluded that the highfallutin scientific jargon of expert opinions that a bitemark, fingerprint, shoe print, tire print, bullet or hair found at the crime scene could only have come from the defendant amounts to nothing but “because I say so.”  But you mustn’t peek, because the report is marked “DO NOT QUOTE OR DISTRIBUTE.”  draft-pcast-report-1-2

Nevertheless, the National District Attorneys Association has lost no time in howling that the report is “scientifically irresponsible” and screaming that it relies on “unreliable and discredited research.” ndaa-press-release-on-pcast-report  Harrumphing that the status quo is fine, just fine, they cry that PCAST “has taken it upon itself to usurp the constitutional role of the Courts and decades of legal precedent and insert itself as the final arbiter of the reliability and admissibility” of forensic evidence. They predict that adopting any of its recommendations would put an end to criminal investigation.

Hell, you’d think a national DA outfit would have the class to at least pretend they care about wrongful convictions. 

What’s great about the PCAST report is that it explains in everyday, non-statistical language exactly why these cops-in-labcoats sciences are based on logical fallacies and circular reasoning. Also how their “reforms” in response to criticism merely beg the question. For instance, “proficiency tests,” where the test-takers can figure out by process of elimination which items match, say nothing about their ability to “match” items in real cases where the right answer may not be there.

Our favorite example of pseudo-reform is the DOJ’s new policy whereby footprint examiners are allowed to testify that a print matches the defendant’s shoe but not to say, “to the exclusion of all other possible shoes.” As PCAST points out, this is meaningless. If an examiner says the defendant’s shoe is the source of the print, he necessarily believes that no other shoe is the source. Even if the DOJ doesn’t get it, any juror would.

But here’s the problem. Remember when the FBI declared that Brandon Mayfield, an American lawyer living peacefully in hippie Oregon, was the Madrid train bomber based on a “100% valid” fingerprint match? Which would have landed him on death row if the Spanish authorities hadn’t convinced the FBI that it wasn’t a match after all?

And remember how the judiciary rose up as one and said, “If the FBI lab, which claims to be the best in the world, could make such a deadly mistake, fingerprinting is obviously dangerously unreliable and we’ll have none of it in the courtroom.”

What, you don’t remember that part? We must have dreamed it.

Then there was the 2009 report by that whoopee outfit, the National Academy of Science (NAS), saying that these “training and experience” sciences are nothing but cop folklore. Just like the Brandon Mayfield incident, the NAS report completely transformed the landscape of criminal prosecution. Trials after 2009 started to look like this:

Prosecutor: I call to the stand Officer Krupke of the Cross-Bronx Expressway Crime Lab. Officer, did you examine Exhibit A recovered from the windowsill of the crime scene?

Officer Krupke: Yes, and I’m ashamed to say I reported that I was 100% certain that it matched the defendant’s fingerprint. But after reading the NAS Report, I realized that was just my subjective opinion influenced by cognitive bias.

The PCAST report not only threatens the amour propre of the DA junta, it’s death to the vested interests of the forensic science establishment. What’s Dr4ensic going to do for a living now? Fill cavities? You can bet your wisdom teeth there’s going to be powerful pushback.

PCAST also assumes that judges give a hang about scientific validity. They oughta know better. Although the report lists a dozen judges as advisors, those are probably the only twelve judges in the country who would dare preclude prosecutor-friendly “scientific” evidence. (And one of them, we happen to know, quit the judging racket precisely because she got tired of getting kicked in the head for trying to do that. She’s now in Academia where everyone is purely dedicated to the truth-seeking process).

Judges happily embrace all kinds of junk science to shore up the cred of prosecution witnesses. The NY Court of Appeals, for instance, has swallowed every kind of “syndrome,” including “hebephilia,” the scientific finding that attraction to teenage jail bait is a psychiatric disorder.  But the judicial attitude to science that contradicts their cherished beliefs remains unchanged since 1610 when the Inquisition indignantly refused Galileo’s invitation to look through a telescope.

As everybody knows, when scientific evidence is offered in the courtroom, judges scrupulously determine its reliability under two distinct legal standards. One for the prosecution and one for the defense.  Experts for the prosecution can send a man to death row by testifying that his teeth match the bite marks in a baloney sandwich. But if the defense had to rely on showing that the earth revolves around the sun, it could be a tough sell to get that in. At the very least, there’d have to be a Frye or Daubert hearing.

The PCAST report is a gold mine for cross-examination and a stiletto for puncturing inflated “scientific” claims. It’s up to the defense bar not to let it go the way of the NAS report, but take it and run with it. After it becomes public, of course.

Addendum: 9/19/2016: the final public report pcast-forensic-science-report-final



About Appellate Squawk

A satirical blog for criminal defense lawyers and their friends who won't give up without a squawk.
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4 Responses to Prez advisors warn: halt convictions based on pseudoscience

  1. Alex Bunin says:

    “And remember how the judiciary rose up as one and said, ‘If the FBI lab, which claims to be the best in the world, could make such a deadly mistake, fingerprinting is obviously dangerously unreliable and we’ll have none of it in the courtroom.’”

    I remember one federal judge from Philadelphia wrote such an opinion … only to withdraw it after much kvetching from DOJ.


  2. TDK says:

    I hate to pick nits, but if you are going to use the example of Galileo Galilei, you might want to research the true story. See “The Great Ptolemaic Smackdown and Down ‘n Dirty Mud-Wrassle” (cf ).


  3. csidds says:

    Reblogged this on FORENSICS and LAW in FOCUS @ CSIDDS | News and Trends and commented:
    Hmmm. I wonder who Dr4ensic might be? The plot thickens. I’m waiting for the American Academy of Forensic Sciences to weigh in on PCAST. That response will either lend considerable credence to PCAST as a “Path Forward” or… well let’s just wait and see.


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