A few weeks ago David Hinkson’s unusual case made its way to the U.S. Supreme Court in the form of a petition for writ of certiorari. Hinkson was convicted by a jury for soliciting the murder of three federal officials. The conviction was a product of government witness, Elven Swisher, who wore a purple heart on the witness stand as he told the jury that he about his extensive combat duty in the Korean War. The problem was that Swisher had yet to join the military when the war ended, and he was never awarded a purple heart. But the jury never learned these facts when they judged whether his testimony was credible. The petition asks the Court to review “two extraordinary rulings” by “a six to five vote” issued by an en banc panel of the Ninth Circuit.
Although Hinkson’s petition raises a number of federal criminal law issues it is, at bottom, a request for the Court to decide whether the lies told by Swisher—the key witness in the case—really did matter to the jury’s decision to convict. Put differently, if the jury knew Swisher was a notorious liar would they have acquitted Hinkson. An en banc Ninth Circuit answered no, but not without considerable dispute both within the court and by a veteran’s group outside the Court, as Adam Liptak at the New York Times reported in November.
The Supreme Court has long noted that determining the weight and credibility of witness testimony is part and parcel of the jury’s role, and they “are presumed to be fitted for it by their natural intelligence and their practical knowledge of men and the ways of men.” Aetna Life Ins. Co. v. Ward, 140 U.S. 76, 88 (1891). The Court’s belief in the jury system is so absolute that in a 1998 case, the Court rejected a plea for military courts to admit the results of a lie detector. The Court forthrightly declared: “A fundamental premise of our criminal trial system is that the jury is the lie detector.”
While no one questions the role of the jury in determining witness credibility, there is substantial disagreement on the ability of juries to detect lies. Cardozo Law School Professor Max Minzner wrote that judges have “generally assumed juries make accurate credibility decisions,” but starting in “the early 1990s, though, legal academics broke from this consensus view based on a series of social science studies demonstrating that test subjects in laboratory experiments correctly determined when a person was lying only slightly more than half the time.” University of Houston Law Professor David Crump used even stronger words: “psychological studies strongly indicate that observers do no better than pure chance in evaluating live witnesses.”
Given the difficulties juries encounter in ascertaining the veracity of witnesses, it is no surprise that cooperating witnesses have lied in the courtroom and led to significant number of wrongful convictions, a number of which have spawned a whole field of scholarship dedicated to ensuring the integrity of the criminal justice system.