Microkhan by Brendan I. Koerner

Yesterday’s Supreme Court decision in favor of the admissibility of deathbed hearsay has attracted a fair bit of attention, primarily because the two dissenters were an unlikely pair: Antonin Scalia and Ruth Bader Ginsburg. Both justices objected to the fact that police officers were permitted to testify about a murder victim’s last words, since doing so deprived the defendant of the ability to confront his accuser. But the court’s majority stuck with centuries of common law, which have held that a dying person’s last words deserve to be heard.

But is that bit of legal tradition rooted in faulty science? I raised the issue in a 2002 Legal Affairs piece that examined why, exactly, we feel that dying people are intrinsically honest—even when they spent their entire lives being quite the opposite. There is precious little research in this field, since experiments are impossible to construct. But one law professor with a medical background believes that dying declarations can’t possibly be as faultless as we’ve long believed:

Rather than attacking a dead person’s moral fiber, defense lawyers would be better off calling into question the reliability of a traumatized brain. In an era of DNA analysis, courts are keener than ever to hear scientific evidence based on laboratory studies. And medical research is fairly unanimous in asserting that murder victims often lack the physical ability to think or communicate rationally.

Bryan A. Liang, a University of Houston law professor, is the foremost advocate of this tactic. A medical doctor as well as a lawyer, Liang has spent considerable time in emergency rooms tending to trauma victims, witnessing firsthand the impaired mental functioning of the gravely injured. “When a person is opened up with a knife wound or is shot, we don’t even think of taking their history, because we know we’re not going to get anything out of it,” he said. “When somebody is deprived of oxygen, when they’re bleeding out of every orifice, [they] just simply are not going to be reliable and sharp-edged intellectually.”

Conducting laboratory experiments on the neurological constancy of the dying is impossible, since their relative dementia before and after the mortal wound can’t be gauged. But according to Liang, researchers have been able to mimic the effects of mild trauma on cognition by placing test subjects in barometric chambers, which simulate rapid, oxygen-depriving changes in altitude. A 1989 study in the journal Aviation, Space, and Environmental Medicine found that healthy young males who underwent such treatment suffered from severely limited functioning, particularly in “intelligence, reasoning, and short-term memory.” It can sensibly be assumed that the effects would be even more extreme for a person whose hypoxia was due to a shotgun blast or extensive third-degree burns.

Read the whole thing and make up your own mind. I’m not saying that dying declarations don’t have a role in the legal system. But each case is unique, and some last words may be more trustworthy than others. Unfortunately, the American legal system doesn’t rarely takes such nuance into consideration.