On Oct. 25, 2023, a 40-year old man named Robert Card opened fire with a semi-automatic rifle at a bowling alley and nearby bar in Lewiston, Maine, killing 18 people and wounding 13 others. Card was found dead by suicide two days later. His autopsy revealed extensive damage to the white matter of his brain thought to be related to a traumatic brain injury, which some neurologists proposed may have played a role in his murderous actions.
Neurological evidence such as magnetic resonance imaging, or MRI, is widely used in court to show whether and to what extent brain damage induced a person to commit a violent act. That type of evidence was introduced in 12% of all murder trials and 25% of death penalty trials between 2014 and 2024. But it’s often unclear how such evidence should be interpreted because there’s no agreement on what specific brain injuries could trigger behavioral shifts that might make someone more likely to commit crimes.
