Posts Tagged ‘expert testimony’

On May 28, 2014, the Pennsylvania Supreme Court published two opinions about whether juries could hear from experts.  In Commonwealth v. Walker, the Court said an expert could tell the jury about the traps and weaknesses involved in eyewitness witness testimony.   But in Commonwealth v. Alicia, the Court  said an expert could not tell the jury about problems with the truthfulness of confessions.   Each opinion featured a different 4-2 vote among six of the Court’s Justices.

This juxtaposition seems so bizarre that the press in our state has noticed.  How does one court, on one day, publish two opinions on virtually the same issue, and end up facing in two completely opposite directions?

The explanation that jumps out from the opinions is the recognition of research and science.    In the Walker majority opinion, Justice Debra Todd discusses how much scientific work on eyewitness testimony has taken place in the last twenty years, since the Court last examined the issue.  In those decades, she says, “advances in scientific study have strongly suggested that eyewitnesses are apt to erroneously identify a person…when certain factors are present, ” and she cites the 2011 opinion of the New Jersey Supreme Court in New Jersey v. Henderson, widely regarded as one of the leading cases on the subject.  The scientific consensus is strong:  “it is beyond serious contention that the statistical evidence on eyewitness inaccuracy is substantial…”  Over the course of the last thirty years, forty-four states have recognized this scientific work and decided that trial courts may allow experts to testify about the problems of eyewitness identification.  Ten of the eleven U.S. Courts of Appeals have done so as well.  (False eyewitness identifications have occurred in almost seventy-five percent of all DNA-based reversals of wrongful convictions.)  Thus Justice Todd and the other Justices in the majority in Walker said that Pennsylvania must recognize the evidence that science has brought to bear.

In contrast, what does the Alicia opinion say about the science on the interrogation of suspects, and how various interrogation techniques may lead to false confessions? (False confessions have occurred in about twenty-five percent of all DNA-based reversals of wrongful convictions.)   Considerable scientific consensus exists on these issues as well; the leading scientists who work on the issue of false confessions published a standard-setting white paper, “Police-Induced Confessions: Risk Factors and Recommendation”  for the journal Law and Human Behavior five years ago. Somehow, this scientific work never even comes up in the Alicia opinion.  It is as if the research on false identifications simply does not exist.

Chief Justice Ronald Castille is at least consistent in these two cases: he wants no experts in court on either eyewitness identifications or confessions, so he dissented in Walker and joined the majority in Alicia.  Castille’s dissenting opinion in the Walker case gives us some insight into the thinking of those who want none of this science before the jury.  In his dissent, Chief Justice Castille scorns the very idea that there could be real scientific work on these subjects.  Indeed, he puts the words science or scientific in derisive quotation marks eight times in just the first three pages of his opinion.  While he admits that “a properly trained chemist can usually reliably explain the chemical composition of a substance,” science about human beings cannot claim any reliability: “studies of human beings, human nature, human perception, and human recollection inevitably have a heavy dose of subjectivity.”   Justice Castille’s position betrays a strong misunderstanding of what science is, and of the process of doing scientific work and of using the scientific method to test a hypothesis.  The real question is not whether we are dealing with so called “hard science” — work done with beakers and bunsen burners.  Rather, the question is whether the work is done reliably and rigorously, according to the scientific method, and in accord with principles and protocols that protect against human biases in the laboratory.  So for now, juries in Pennsylvania will have to do without the best scientific knowledge on why we might have false confessions.

But, even more important, the issue of whether experts can testify on these subjects is not a new one; courts in most jurisdictions resolved this issue years ago.  Instead, every institution that forms part of our criminal justice system in PA should be focused on prevention: establishing protocols for police to follow that will keep dangerous mistakes  eyewitness testimony and interrogation from happening in the future.   The research is there; the best practices are known.  Nevertheless, we remain stuck in the past, arguing about expert witnesses.



With thanks to the Wrongful Convictions Blog, I learned that Michigan’s Supreme Court has  issued a decision on the issue of false confessions.  It’s one step forward and two steps back.

This type of testimony can be vital, given the power of confessions to convince juries.  According to Richard Leo, a psychologist/law professor and author of the multiple-award-winning book Police Interrogation and American Justice (Harvard, 2008), most people cannot accept that an innocent person would ever confess to a serious crime.  (Full disclosure: Richard Leo provided an endorsement for my book Failed Evidence.)  Despite the fact that 25 percent of the 300 cases of defendants exonerated based on DNA featured a false confession or false plea of guilty, people cling to the myth that no one would confess falsely, absent torture, mental infirmity, or lack of sobriety.

Thus it was heartening to see People v. Kowalski, decided July 30, in which the Michigan Supreme Court declared that a defendant could present expert testimony on why a person might confess falsely.   While an expert could not comment on truthfulness of the defendant in the case, expert testimony on false confessions and how they happen is admissible because what lies behind false confessions is “beyond the common knowledge of the ordinary person….”

So far, so good.  But the court then went on to exclude the expert testimony in the case, based on Michigan’s version of Evidence Rule 702 and the Daubert case.  The court said that the methodology used to generate its conclusions was unreliable.

That testimony was given by Professor Richard Leo  — the same person who wrote Police Interrogation and American Justice, and so many of the other seminal works that help us understand today that the idea that an innocent person would never confess is a myth.  Professor Leo’s body of work has been widely published, and much of it has been peer reviewed — two important factors for reliability under the Daubert rule.  And the research and conclusions he presented in Kowalski were generated independent of any work he did as an expert in the case.

What gives?  It’s an example of a phenomenon I discuss in Failed Evidence: the Daubert rule is applied much more stringently to evidence advanced by the defense than to evidence that comes from the prosecution.  More on that when the book is published, in September.