Magnetic resonance imaging has been hailed as a possible means of creating the ultimate lie detector. Yet the first publicized fMRI evidence admitted into a US court was not used to separate fact from fiction, but to prove that a murderer was a real psychopath. Brian Dugan was already serving a life sentence for two murders when he was indicated in the 1983 rape and murder of a third, Jeanine Nicarico. In July of this year, Dugan pleaded guilty to killing the young girl. During the sentencing hearings that followed, Dugan’s lawyer, Steve Greenberg, introduced fMRI scans as evidence that his client suffered from a clear case of psychopathy. While Dugan was ultimately sentenced to death, the jury’s 5+ hour deliberation of the case may indicate that fMRI scans could become an important tool for defense attorneys in the US legal system.
Greenberg’s expert witness was Dr. Kent Kiehl, a researcher at the University of New Mexico. Kiehl regularly performs fMRI scans on prisoners as part of his studies in psychopathy and moral reasoning. According to Kiehl, Dugan has 37 out of 40 markers for the condition, placing him in the 99.5 percentile. Yet the prosecution argued, with the help of its own expert Jonathan Brodie of NYU, that a mental illness such as psychopathy does not mitigate the results of Dugan’s actions and that a scan in 2009 could not accurately reflect the state of mind of someone in 1983. The jury deliberated for five hours, notified the judge that they had reached a decision, but then asked for more time. Following a sequestered night, the jury met again before delivering the death sentence. The jury, before returning for further deliberation, was originally looking to give Dugan a life sentence, so Greenberg is seeking an appeal.
While PET scans, and brain abnormalities have been used in cases before, this is the first time that a fMRI scan has been admitted as evidence of a defendant’s mental or moral state. Of course, sentencing hearings in the US are less strict than trials in the admission of evidence. We are a long way away from knowing if fMRIs can be accepted as proof that a defendant (or witness) is lying about an event.
[photo credit: Sun Times]