Reliability and Credibility

[Note: Friends of Justice is a personal blog. I speak only for myself.]

[Courts have] a responsibility to ensure that evidence admitted at trial is sufficiently reliable so that it may be of use to the finder of fact who will draw the ultimate conclusions of guilt or innocence. That concern implicates principles of constitutional due process. “Reliability is the linchpin” in determining admissibility of evidence under standard of fairness that is required by the Due Process Clause of the Fourteenth Amendment. Competent and reliable evidence remains at the foundation of a fair trial, which seeks ultimately to determine the truth about criminal culpability. If crucial inculpatory evidence is alleged to have been derived from unreliable sources, due process interests are at risk.

State v. Michaels (1994) citing Manson v. Brathwaite, 432 U. S. 98, 97 S. Ct. 2243
(1976)

I am posting a link to an article, by Robert Rosenthal, that I believe should be required reading for every law student intending to enter criminal practice, either as a prosecutor or as a defense attorney.

One of the most useful things Rosenthal does in this article is to explain clearly the difference between the commonly confused concepts, reliability and credibility:

Understanding the meaning of reliability in the legal context has proven difficult for many lawyers and jurists, as well as scientists attempting to be heard and understood in a courtroom. A primary source of this difficulty is the frequent confusion between “reliability” and two other legal terms: “credibility” and “competence.”

“Competence” refers to the capability or capacity of a particular individual to serve as a witness. Persons are deemed competent if they are sufficiently intelligent to observe, recollect, and recount an event, and have a moral sense of obligation to speak the truth. 3 The determination regarding a witness’ competence is a legal one, made by the trial judge before testimony is given. 4 The competence standard is not very demanding. The vast majority of people offered as witnesses are deemed — and are — competent to testify in a trial. Competence is presumed, and therefore it only becomes an issue in cases involving young children or individuals whose capacity to observe, recollect, and recount is impaired or undeveloped.

“Credibility” refers to how believable a witness is. The credibility of a witness’ testimony is an assessment made by the jury’s it considers each witness’ statements and the challenges to those statements made through cross-examination and contradictory evidence. The jury’s responsibility to determine the credibility of each witness’ testimony is no different than any listener’s judgments about whether a speaker is telling the truth. In the context of a trial, credibility determinations are not matters of law to be decided by the trial judge. Rather, the jury is solely responsible for making these credibility assessments.

Whether evidence is “reliable” is a legal matter that is decided by the trial judge before the evidence is presented to the jury. Unlike “competence,” reliability does not concern the personal characteristics of witness. Unlike “credibility,” reliability does not concern the believability of witness. “Reliability” concerns the inherent quality of evidence.

Evidence is reliable if it is what it is purported to be. For example, photograph is reliable as evidence at trial if it accurately represents the scene that it purports to represent; that is, the scene of the crime at the time it occurred. Similarly, if a witness sees the occurrence of crime and then identifies the perpetrator, that identification testimony is reliable because it is what it purports to be: n identification of the person who committed the crime. If, however, the witness could not positively identify suspect until investigators suggested that a particular person was in fact the perpetrator, the witness’ identification may not be what it purports to be. It may be reflection of the suggestion rather than the witness’ own identification. Because there is no way to differentiate between the two, the identification that is made after suggestion is deemed unreliable and inadmissible at trial as a matter of law, and the jury would never hear about it. 5 Other examples of evidence deemed inadmissible for want of reliability include testimony produced through hypnosis, which may be the product of the hypnotic suggestion rather than reflection of the witness’ experience, 6 and out-of-court statements elicited through suggestive or coercive questions. 7

Each piece of evidence offered at trial is subject to a reliability determination by the judge. For example, if the prosecutor in a trial involving cocaine possession wishes to present bag of cocaine, the prosecutor must establish that the bag of cocaine presented in court is the same as the bag of white powder taken from the defendant at the time of his arrest. To do this, the prosecutor must demonstrate a “chain of custody” documenting the whereabouts of the bag of powder from the time it was collected by the police through the trial. The chain of custody provides an assurance that the cocaine presented at trial is what it purports to be: the bag of white powder confiscated from that particular defendant at the time of the arrest.

It is understandable that lay people and journalists often confuse credibility and reliability. What is neither understandable nor forgivable is that so many judges, prosecutors and defense attorneys either don’t know the difference or simply don’t care.

Testimony produced by the coercive questioning of children is not reliable. (Indeed, coercive questioning can produce unreliable testiminy in adults as well.) This is not to say that such testimpny is necessarily false. But since no jury should hear unreliable evidence in the first place, no jury should have to decide its credibility.

Testimony based on memories previously “repressed” memories is not reliability. No jury should hear such evidence and judge its credibility.

Few (if any) scientists argue for the reliability of evidence produced by coercive questioning or based on repressed memories. Part of the problem is that lawyers, including judges, have little understanding of what science is and often treat non-scientists, such as psychotherapists, as if they were scientists.But if psychotherapists qualify as scientists, then so should astrologers and phrenologists.

A few years ago the Massachusetts Supreme Judicial Court disgraced itself when it, without dissent, refused to grant a new trial to the obviously innocents defendants in the Fells Acres case. If any of those judges understoon the difference between reliability and credibility, they held their tongues for political reasons.

Soon the massachusetts Supreme Judicial Court will hear the new-trial motion for the Paul Shanley case. Once again, they will have to decide which is more important: politics of the United States Consitution.

I wish their past performance gave us more reason to hope.

-Bob Chatelle