[LUM#1] Justice: Is the Brain the Deciding Factor?
Thirty years after DNA evidence was first introduced in court, could the brain be the new frontier in criminal evidence? While “neurolaw” appears to hold great promise, its emergence currently raises more questions than it answers.

In 2008, a court in the Indian state of Maharashtra made headlines by becoming the first to admit, as evidence against the defendant in a criminal trial, findings from a neuroscientific assessment. Accused of being responsible for the death of her boyfriend—who had been poisoned with cyanide—a young woman was found guilty based on a brainwave pattern, a test conducted using an electroencephalogram. Betrayed by her own brain, Aditi Sharma was sentenced to life in prison. A few months later, the young woman regains her freedom after the Indian Institute of Neurosciences takes issue with the use of a method that is controversial, to say the least.
“Detecting lies through brain imaging poses a number of problems, particularly that of interpretation,” says Marie Christine Sordino, a professor of criminal law at the Montpellier Law School, who has been studying the emergence of “neurolaw” for several years. “In the case of this young Indian woman, the reaction to the word ‘cyanide’ could have had multiple causes—it could have been linked to the emotion triggered by the trial, the death of her boyfriend, or something she had read online… Furthermore, not all neurologists agree on how to interpret the data. For all these reasons, there are serious doubts about the admissibility of the evidence,” she explains .
The Indian case and its unexpected outcome illustrate the scope of the questions and doubts surrounding the emergence of neuroscience in the legal sphere. With the passage of the bioethics law in July 2011, France took a tentative stance on the subject and left the door slightly open to the use of neuroscientific evidence, without, however, specifying in which cases or for what purposes. To date, it is the only country to have enacted legislation on this issue.
Free Will and Determinism(s)
Others did not wait for a legal framework to be established before rushing to fill the gap. The use of neuroscience in court cases is said to have tripled worldwide between 2005 and 2011, and it is in the United States that neuroscientific evidence has been most successful. Brain imaging is increasingly accepted there as a mitigating factor, with lawyers no longer hesitating to explain their clients’ behavior by citing brain dysfunction: abnormal size of the frontal lobes or amygdala, lesions affecting the area responsible for regulating aggression or judgment… This can result in clients avoiding several decades in prison.
Far from being limited to lie detection, neuroscience thus opens up entirely new perspectives on how to understand criminal behavior. And it reignites the debate over the supposed biological origins of criminal behavior—an old chestnut for an entire school of thought within criminal science. “In the 19th century, the Italian Lombroso explained that there were physical profiles of offenders: murderers, for example, were said to have bushy eyebrows, while thieves had long hands… This quest continued with genetics and the search for a ‘crime gene.’ “We are now trying to find answers within the brain itself,” summarizes Marie-Christine Sordino.
These answers are enough to send a chill down one’s spine. By suggesting that individuals face a fundamental neurobiological inequality, neuroscience threatens to shatter the concept of criminal responsibility, which is currently at the heart of the judicial system. “We know that free will is constrained by environmental and social determinants…” And therefore neural ones as well? The criminal law scholar admits to being perplexed by questions that interest both legal scholars and philosophers alike. For the implications are vast—even abysmal.
The Temptation of Scientism
It is, in fact, the very existence of free will that is being called into question. “If we are entirely determined, the concepts of individual responsibility or moral judgment lose all meaning. We would then have to rethink everything, including Enlightenment philosophy and the vision of a rational individual,” confirms Marie-Christine Sordino. “The risk is the scientistic temptation toward a form of justice that seeks to explain everything through the brain, or even predict certain behaviors,” warns Ms. Sordino.
However, many unknowns remain. The issue of causality, in particular: “At what threshold of brain abnormality can we consider a person dangerous—likely to commit a crime? Can this threshold even be defined?” the legal scholar asks . “The current state of knowledge does not allow us to resolve these questions. We must be all the more cautious,” she warns , “given that the expert’s influence is very significant today. “The use of brain imaging scans would clearly have a major influence on jurors.” But faced with ever-increasing demands for transparency and scientific objectivity, the justice system seems unable to avoid reflecting on techniques that could one day—perhaps not too far in the future—revolutionize the day-to-day operations of courtrooms.
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