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John Balint is charged with murder. Balint claims self-defense. He testifies that he honestly thought the man he killed was threatening him with a gun. The evidence at the trial shows that the man was not armed. The issue for the jury is whether Balint honestly but also reasonably believed the dead man had a gun. In rebuttal, the prosecutor offers the results of the Brain Electrical Oscillations Signature (BEOS) test performed on Balint. In his closing argument, the prosecutor asks the jury: "So, which do you believe, Mr. Balint's buzzing brain or his lying eyes?"
In twenty-five years, this question may be unremarkable in criminal trials around the world.
In June 2008, a judge in India convicted a woman of murdering her former fiancè, based in part on evidence generated by the BEOS test. According to the neuroscientist who invented BEOS, the technology is capable of identifying, through electrical activity in the region of the brain where memories are stored, events that a person has actually experienced or conduct in which the person has engaged.
In the case of the woman in India who was convicted using BEOS, investigators hooked her to the machine through electrodes attached to her head and read aloud to her what they thought had happened on the night her former fiancè was killed. As the woman sat silently, listening as the facts were read to her, regions of her brain lit up. The judge who convicted her concluded that the test demonstrated the woman had "experiential knowledge" that only the killer would have had.
When I first heard about a person being convicted of murder using the BEOS test, I assumed the test was some type of fake lie detector concocted to obtain a confession from the woman. Stories abound about police investigators using fake lie detectors. One version of the story is that investigators place a colander on the head of their suspect with wires connected to the office copying machine. Whenever the suspect gives a "wrong" answer, one of the investigators hits the print button and the "lie detector" spits out a copy that reads: "He's lying." Eventually, the suspect confesses.
Whether BEOS turns out to be a fake lie detector remains to be seen. Although a committee of government-appointed experts concluded that the BEOS technology is "unscientific," it is gaining a foothold as an investigatory tool in several Indian states.
American researchers currently are trying to perfect brain-scan lie detectors, using electroencephalogram (EEG) and magnetic resonance imaging (MRI) technologies. One neuroscientist used "brain fingerprinting" to show that an Oklahoma death-row inmate who claimed to be innocent did not have knowledge of several key facts about the murder for which he was convicted. Ultimately, however, the court summarily rejected the uncorroborated test results as legally insufficient, and the inmate was subsequently executed.
I doubt that BEOS, brain fingerprinting, or other types of brain-scanning lie detectors will be accepted anytime soon in criminal trials in this country; the constitutional obstacles will be great, and courts generally are suspicious of lie detectors and truth serum. But an interdisciplinary group at Duke has been formed to consider the feasibility of using neurobiology to identify false and unreliable testimony. Such technology might be useful in a wrongful-conviction investigation, for example, to demonstrate with more conventional corroborating evidence that a witness who recants childhood testimony of sexual abuse is telling the truth. Or that an eyewitness whose unreliable testimony put an innocent person on death row could not have seen the homicide.
Twenty-five years from now, which are you going to believe: his buzzing brain or his lying eyes?
