The Brain Defense: A Real-Life Legal Thriller for Science Buffs

Crime writer Kevin Davis’s new book The Brain Defense: Murder in Manhattan and the Dawn of Neuroscience in America’s Courtrooms is a real-life legal thriller that science buffs will love.

Sixty-five year-old Herbert Weinstein was, by all accounts, an even-tempered, friendly man. Not a mean bone in his body. So when he tossed his wife Barbara out of the 12th story window of their Manhattan apartment building, there were plenty of questions and very few answers. Even Weinstein couldn’t explain why he had done it. Then they discovered the cyst: a fluid-filled lump the size of an orange squeezing the frontal lobe of Weinstein’s brain.

Was Weinstein responsible for his own actions? Or was the cyst? The results of the Weinstein trial would have enormous implications for the criminal defense system. If one person could get away with blaming his brain for an act of violence, so might anyone else. Where would it stop, and how would the notion of free will and personal responsibility fit in a system like that? Would this be the twentieth century version of “The devil made me do it”?

With Weinstein’s case as a lodestone, Davis embarks on a journey into uncharted lands where cutting-edge neuroscience and centuries of criminal law intersect.

The question of whether or not a mentally incapacitated person should be held responsible for his or her actions is one that dates to antiquity. Even the ancient Romans made provisions in their laws for individuals thought to be non compos mentis, or “not of sound mind.” English law recognized such circumstances as well.

The influence of these age-old ideas can still be seen in our own modern legal system, with the only real difference in Weinstein’s case being the technology that allowed the court to actually see a physiological abnormality. Magnetic resonance imaging, or MRI, had only recently come into its own, with the first human body scan performed less than two decades earlier. This new technology, along with other diagnostic tools, enabled diagnosticians to narrow in on, and describe, Weinstein’s neurological abnormalities in ways that simply wouldn’t have been possible just years prior.

Brain abnormality or not, Weinstein’s diagnosis didn’t make his an open and shut case. Not every person who suffers a brain injury goes on to commit an act of horrific violence. Most of them don’t, obviously. Whether it’s having a second slice of cake or cheating on a spouse, people experience and override ill-advised impulses all of the time. Why should Weinstein receive any special consideration?

Barring more erudite questions about free will and brain anatomy, there was — and remains — another troublesome aspect about Weinstein’s case and others like it. Even if the presence of a neurological irregularity is justifiable as a mitigating circumstance, what is there to say for defendants who may have similar brain abnormalities but cannot afford the tests that could prove their existence? Was this, as one assistant district attorney described it, a “rich man’s defense”?

Questions suggested by the Weinstein case, as well as similar ones described in The Brain Defense, are likely to become even more important as our knowledge of the brain improves. It might be difficult to imagine a future in which an MRI scan could absolve a murderer of responsibility for his or her crime, but a better understanding of the complexities of neuroanatomy and behavior might enable the medical community to prevent the act entirely.