Science and the Law Don’t Mix

The New York Times pre-announcement of the report of the of the National Academy of Sciences report on the junk science used by prosecutors in the courtroom promises a scathing critique.  It’s touted as a “must read” for criminal defense lawyers, and no doubt it will be.  But.


This is not a judicial ruling; it is not a law,” said Michael J. Saks, a psychology and law professor at Arizona State University who presented fundamental weaknesses in forensic evidence to the academy. “But it will be used by others who will make law or will argue cases.”

Legal experts expect that the report will give ammunition to defense lawyers seeking to discredit forensic procedures and expert witnesses in court. Lawyers could also use the findings in their attempts to overturn convictions based on spurious evidence. Judges are likely to use the findings to raise the bar for admissibility of certain types of forensic evidence and to rein in exaggerated expert testimony.

Anyone who tries cases for a living, and has enjoyed the experience of some insane government witness tell a jury, with a look so sincere that you just want to take him home and love him, that it’s impossible to get fingerprints off a nice, shiny chrome pistol, is left to ask one question.

Who’s going to be the one to shut down prosecution witnesses spouting all the traditional junk science nonsense that has put tens of thousands of people in prison for the last few generations?

For those of us who spend a bit of time monitoring the decisions on new “science” in the courtroom, and watch with incredulity as judges shrug and take the word of very official sounding pseudo-experts who proclaim the infallibility of whatever scientific tripe they are selling, writing about or spent the last  months learning at the Government School for Expert Witnesses, one thing is painfully clear.  Judges have no more clue what good science is then we do, and when asked to pass on the accuracy of expert testimony in some scientific endeavor, invariably turn to the research to see if some other judge has already allowed it.  If so, it comes in.  If rejected, it doesn’t.  If truly novel, God help us.

Am I being silly?  Ask any cop who takes the stand to explain that some mope blew a .18 on the Intoxilyser 5000 how the little black box figures that out.  He won’t know.  It’s a box.  It shows a number.  That’s it.  Object and the judge will look at you like you’re nuts.  Everybody knows the Intoxilyser 5000 is admissible.  Why?  Because one judge somewhere held a hearing and said so.  After that, the rest of them go along for the ride.  When the day comes that they figure out that the little black box may not be quite perfect, they will have a new little black box that is “much more accurate.”  But if the new one is much more accurate, doesn’t that mean the old one was inaccurate? 

This report could blow the roof off junk forensic science.  But only if judges across the country chose to care.  The report itself will never find its way before a jury.  Sure, we’ll question witnesses about it, just as we do now to challenge the actual scientific underpinnings of their “expertise”.  And the judges will let these pseudo-experts testify anyway, just as they do now, because they feel that there’s no other choice.  Once one judge opens the gate, it’s open forever.  That’s how science in the courtroom works.

The use of dubious science is so routine in courtrooms that experts are frequently avoided by having a cop testify that he took a course at the Academy and can now testify on all manner of forensics.  The beauty of this testimony is that it’s purely conclusory, the cop either explaining that he doesn’t know why something happens, but that he knows that it’s 100% reliable.  The judge just nods.  That’s all it takes to get something in front of a jury.  I’ve seen judges allow expert testimony from agents with all of 37 minutes of experience come in as if he’s a professor emeritus from MIT.  Over objection, naturally.

The sad fact is that science and law don’t mix.  Lawyers aren’t scientists.  Judges aren’t scientists.  We hear the words that come out of true expert’s mouths and it gives us a headache.  We study up in advance of testimony and become overnight “experts” as best we can, but we are constrained to accept the popular notion about what is and is not real because the literature can’t make us truly understand all the chemistry, physics, biology, etc. needed to bring us from the core science to the junk spoken from the witness stand.

I applaud the National Academy of Sciences for having done this study, and for having overcome the government’s opposition to anyone challenging their self-serving insular control over what constitutes valid scientific evidence.  But this report alone won’t do anything if judges, each and every one of them, won’t take the responsibility to put an end to witnesses spouting nonsense in the name of science and for the goal of convictions in front of a jury. 

19 comments on “Science and the Law Don’t Mix

  1. Windypundit

    For me, this is one of the most intellectually troubling issues in law. I have some passing knowledge of how scientists test and develop support for their theories. I also have a vague idea of how lawyers prove things to fact finders in the courtroom. And as far as I can tell, the two methods of finding truth seem incommensurable.

    I’m sure greater minds than mine have examined the problem, and I hope they found some practical solutions that the courts could adopt, if only we encourage them. I wish I knew what they were…

    At the very least, courts should never accept claims of sole-source expertise. The accuracy, reliability, and robustness of any scientific process or discovery is established only by successful testing and duplication. Anybody who claims to be able to reliably and accurately analyze evidence in ways that nobody else can duplicate is either fooling themself or trying to fool you.

  2. SHG

    While not discussed in this post, bear in mind the weight jurors give “expert” testimony.  If someone claiming to be an expert says that a test is conclusive proof, then conclusive proof it is.  This is particularly galling given the frequency with which courts allow agents and cops to testify as “experts” based on their “experience and education,” consisting of a special course in cop school or their vast experience in everything ranging from drug testing to accounting methodology to the secret language of drug kingpins.

  3. Jdog

    “And what response did the Veridicator 2012 give upon its operation, Officer?”

    “It said, and I quote: ‘Answer hazy; ask again later.'”

  4. Windypundit

    Sigh. “Based on my experience and education I determined the individuals were congregating in a location frequented by gang members, wearing clothing characteristic of gang members, had haircuts and tattoos characteristic of gang members, were making gestures characteristic of gang members, had cell phones and beepers of a type common to gang members, wore jewelry typical of gang members…”

  5. jigmeister

    Read in a stipulation that all experts are wrong half the time and then let them all testify. Better yet, a jury instruction.

  6. SHG

    All experts are wrong half the time, or half experts are wrong all the time?  We would just never agree on which half.  I would spend the whole time the stip/instruction was being read pointing at the other table.

  7. Jim Keech

    It can get even worse. In Washington, the courts were building quite a record of finding flaws in the Datamaster BAC machine. The Legislature decided that was awful and made the results admissible as a matter of law. Even the judges aren’t particularly happy with that scenario, but we’re stuck with it.

  8. SHG

    The Kentucky Legislature today enacted a law declaring that the sun rises in the west and that all out of state truckers driving across state lines with shadows going in the wrong direction shall be guilty of witchcraft and burned at the stake.

    So how exactly does a legislature declare evidence admissible as a matter of law?  Any separation of power issue there? 

  9. Larry Daniel

    As an “expert” who specializes in criminal defense, I can assure you that in my field, the lack of an expert can lead to big trouble for the defendant.

    The prosecution has had a bit of a free ride due to the lack of experts in computer forensics who will work for the defense.

    It is so easy to use computer evidence out of context that makes the evidence support the prosecution’s case, when if clarified, may very well have the opposite effect.

  10. SHG

    In many cases, the defense has a good idea that expert testimony will be used at trial and an opportunity to prepare to rebut it.  Whether they can afford to do so is another matter, but at least they know.  But in a surprising number of cases, the expert testimony comes in on some small detail, unanticipated, or a somewhat collateral issue, and the defense is sandbagged.  It’s not easy to find an expert in the middle of trial, get a hold of him, prep him and get him in to testify, again assuming they can afford it.  The variations on this theme are many, and the impact often devastating.

    When the defense has deep pockets, all of this is far easier to address.  When the defense is on a shoestring, it’s impossible.  Also, and this is a far bigger issue than people imagine, finding true experts can be extemely difficult.  Finding experts willing to testify for the defense can be impossible.  Finding experts who are responsible and responsive can be a nightmare.  We throw the word “experts” around quite casually, but there’s nothing casual about using expert witnesses.

  11. SHG

    Aha.  Well, if a trial court can’t screw things up badly enough, there are always appellate courts to do the job.

  12. John David Galt

    This same problem arises frequently in civil cases, especially those over products and services (including doctor malpractice) that are alleged, on very speculative grounds, to have caused severe injury or disease. It seems to me that juries are much too willing to award huge amounts to plaintiffs, often forcing companies or products out of the market when the evidence doesn’t really merit such a huge penalty.

    As I see it the root of this problem, and the only possible solutions, reside in the jury selection (“voir dire”) system. First, I would eliminate all peremptory challenges, which always seem to be used to purge the smart people from juries and leave only sheep. Second, I would require that any jury which is going to hear a scientifically controversial theory such as “Alar causes cancer!” include at least two or three scientists with the expertise to evaluate that claim and the credentials to back it up.

    And third, I’d like to see any verdict that would have the effect of shutting down a huge company require legislative approval before it can take effect. No jury should be able to destroy large chunks of the economy.

  13. a

    Interesting points. I agree entirely that having smarter or better-educated jurors would help. On my last jury duty, I talked almost nonstop for over two days to turn around every other juror, because I had paid attention during high school science classes and knew that the “scientific” claim being presented made no sense at all. And having more than one expert to evaluate claims would help also.

    I’m iffy on number three, though. I can understand your concern about having one small group of people having such power, but some many legislators are bought and paid for that I don’t trust them to do the right thing. Maybe some other secondary process could be put in place.

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