fMRI on Trial
Last year, one of the most-followed trials in the Chicago area was the first-degree murder case against Brian Dugan, who was accused of murdering a 10-year-old Naperville girl in 1983. The Dugan trial was interesting for many reasons, most notably for coming at the end of a 26-year process during which two other men were falsely convicted and sentenced to death for the crime. But it wasn’t until I read this week’s issue of Nature that I realized the scientific precedent set during the trial, one that signaled a new intersection of science and law that could be very important in coming decades.
During the sentencing portion of the trial, after Dugan had been convicted of the murder, testimony for both the defense and prosecution was provided by neuroscientists. This occurrence in and of itself is not unusual, as scientific evidence is more and more frequently used to argue whether a criminal suffers from mental illness that contributed to the crime. But as reporter Virginia Hughes summarizes nicely, this courtroom science debate was different, as it hinged upon new evidence for mental illness: an fMRI brain scan.
Through his defense team, Dugan had been volunteered for a study conducted by Kent Kiehl from the University of New Mexico on the brains of psychopaths, people who lack a sense of moral behavior. According to Hughes’ article, Kiehl has conducted fMRI scans – which create a live movie of brain activity – on more than 1,000 criminals over 16 years, including many that used a mobile scanner located at a prison in New Mexico. Dugan, already in police custody for two other murders, was scanned by Kiehl at Northwestern Memorial Hospital during his trial and interviewed by Kiehl for a diagnosis of psychopathy.
But when defense lawyers attempted to introduce the results of the scan and interview into court as a “mitigating factor” that could save him from the death penalty, prosecutors objected. Hughes writes that DuPage County State’s Attorney Joseph Birkett argued in court that the scans would prejudice the jury due to “bright colors and statistical parameters…chosen by the researchers.” A hearing held outside the jury’s presence led the judge in the trial to rule that the results of Dugan’s scan could be discussed, but not shown in the trial. After some more legal oddness unrelated to the brain scans, Dugan was eventually sentenced to death in November 2009.
Though somewhat irrelevant to the details of the case, the role that fMRI scans played in Dugan’s sentencing could open the floodgates of a phenomenon speculated about for quite some time: the use of brain imaging in courtrooms. Hughes’ article does a great job of rounding up scientist opinions about this use – both against and, perhaps surprisingly, for – so I won’t recapitulate those here. But the central argument against brain scan “diagnosis” of mental illness is worth remembering for all brain scan studies – most such research uses average pools of data from multiple subjects that can’t always be applied on an individual basis. As Hughes reports Jonathan Brodie, a psychiatrist from New York University, said in the trial, “If you look at professional basketball players, most of them are tall…but not everyone over six foot six is a basketball player.”
There’s a nice overview of this article and some other research into brain imaging of mental illness by Vaughan Bell at Mind Hacks.
In another crossover of science and law enforcement, a PNAS study suggested that the thriving worlds of bacteria present on everyone’s skin (gross but true) could be employed as a forensic tool. Specifically, the authors proposed that by testing the bacteria present on a computer mouse or keyboard, they could identify people who had recently used those devices – a useful police tool for determining who hacked into a system or deleted incriminating data. And as Ars Technica and Wired report, it worked, putting the old-fashioned fingerprint duster on notice.
Science-writing kerfuffle! I normally think that the science writers at UK newspaper The Guardian are some of the best around (and their sportswriters are the best), but boy is this article wrongheaded. I just wrote about epigenetics on the blog recently, and will do so again many times in the future, but nowhere will I ever claim that it proves Darwin wrong, because that’s just, well, wrong. Jerry Coyne, Carl Zimmer, and another Guardian reporter have already torn it to shreds, it’s worth reading like a car accident is worth gaping at.
Should people be allowed to donate their organs to strangers in exchange for money? A recent survey from the University of Pennsylvania said that payment for organ donation would increase supply without drawing disproportionately from the poor, but the University of Chicago’s Lainie Ross criticized their conclusions.