The Brain in the Courtroom

“Once it becomes clinically relevant, it will become legally relevant.” – Francis Shen

Writer: Ebani Dhawan
Editor: Emma Last
Artist: Sophie Maho Chan

In 2002, Sheila Berry bashed her friend to death using a large cinder block in a fit of inexplicable rage. Only months later, Berry had a brain tumour removed. This tumour was shown to be connected to Berry’s rage – as the tumour grew, so did her aggression. Post-surgery, Berry’s aggressive behaviour essentially vanished. Years later, a jury in Massachusetts found her guilty of first-degree murder. However, in 2014, the Massachusetts Supreme Court decided that it was a miscarriage of justice to hold Berry responsible, especially after the testimonial of a neuroscience expert detailing how the location of her tumour was apt to cause problems with disinhibition and aggression. 

This is just one of the ways the brain is finding its way into the courtroom. Over 1500 judicial opinions between 2005 and 2012 have mentioned neurobiological evidence – essentially an argument suggesting that their “brains made them do it”. Evidence, which can be anything from brain scans to neuropsychological exams, is being used in more and more legal cases of all kinds. An analysis of US criminal cases found that 60% of sampled cases involved non-capital crimes, such as robbery and fraud – cases that we don’t necessarily think require neurobiological evidence. 

When thinking about using neuroscience in the courtroom, our imaginations often drift to situations where volition and choice of the perpetrator are questioned. However, these concepts are not well-understood by scientists yet. Although there may be some insight, it is mainly at the population-level, which does not tell us why a specific person acted the way they did. Thus, neurobiological evidence is not as commonly used to determine guilt or innocence as we might believe.


Rather, such evidence is intertwined in sentencing decisions. When dealing with juveniles, developmental neuroscience has aided constitutional prohibitions against life imprisonment. Understanding that the adolescent brain is in a transitional stage of limited executive control can inform long-term sentencing and culpability. Beyond juveniles, neurobiological claims aid in mitigating sentencing, including by arguing that the defendant’s counsel was incompetent as they failed to introduce neurobiological evidence during the sentencing period of the trials. Introducing such evidence has been found to decrease death sentences, reduce guilty verdicts, and reduce sentence length in some cases. 

As neuroscience is increasingly being used in the legal system, it opens the possibility to bring different sorts of claims, such as “invisible” tort injuries. This would include post-traumatic stress disorder, emotional suffering, and traumatic brain injuries. With the ability to peer into the brain’s perception of pain, this could revolutionise how we think about tort law and compensation. We no longer should limit tort claims to physically visible injuries. Tort law should reflect the strides society has made in matters regarding mental health and recognise that invisible injuries can be as debilitating as those we can see. 

Painting a utopian vision of neurolaw would be remiss. The differing paradigms between the scientific and legal communities creates murky waters. Neuroscience is objective and needs to meet a certain threshold of reliability. As useful as brain scans are, they are simply proxy measures of brain function. Human subjectivity is inherently embedded in the interpretation of neurobiological data, which could lead to doubts of credibility. The legal system and judges need to be aware of its interpretations and manipulations, and the impacts on jurors. 

There are also issues with consistent definitions of behaviours. Behaviours are complex and subject to environmental influence, making them difficult to measure.  Science can inform the law, but ultimately, cannot dictate it. 

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s