Reports Show Neuropsychological Evidence is Growing as Defense in Trials

December 9, 2013 Updated: April 24, 2016

The Supreme Court is reviewing how this type of evidence will be allowed in court. There has been a surge in America recently in the number of defendants claiming that their brains were to blame for the crimes they committed. Criminal courts in the United States are relying on controversial, unproven neuroscience along with questionable MRI scans used as evidence in criminal trials. A legal expert who sits on Barack Obama’s bioethics advisory panel has warned the president. Nita Farahany, a professor of law, was addressing a Society for Neuroscience meeting in San Diego when she reiterated what she told the president.

Farahany said that those on trial have been mounting defenses that are ever more sophisticated. In an effort to show they were not fully responsible for murders and other felonies, they drew on neuropsychological evidence. That evidence has been used widely by criminal defense lawyers to reduce defendants’ sentences but in a significant number of cases, neuropsychological tests and brain scans have been used to clear defendants of all responsibility.

Subsequent to an analysis of over 1,500 judicial opinions between 2005 and 2012, the rise of (so-called) neurolaw cases has mounted concerns. Brain science first appeared in murder cases, said a Denver criminal defense lawyer, but now it has spread to other crimes including sexual assaults and child molestation. “What is novel is the use by criminal defendants to say, essentially, that my brain made me do it,” Farahany said. How such evidence can be used in criminal cases is now being reviewed by The Supreme Court.

Farahany said she is expanding her research abroad, including the UK, since scientific and legal experts foresee the trend spreading to other countries. Very few criminal defense lawyers turn solely on neuroscience evidence. However, a survey has found many cases where defendants had used neuroscience to argue that their confessions should be struck out, as they were not competent enough to provide them. “When people introduce this evidence for competency, it has actually been relatively successful,” said Farahany.

There are cases where strong proof has been established in the validity of abnormalities in the brain causing criminal behavior. The case of a 40-year-old schoolteacher from Virginia is one such case. Russell Swerdlow and Jeffrey Burns, neurologists at the University of Virginia medical center, studied the case in 2002. The teacher suddenly developed impulsive pedophilia and was convicted of child molestation.

Before his sentencing he complained of being unsteady on his feet and a sever headache. Doctors found an egg-size tumor in his right orbitofrontal cortex that once removed ended the man’s sudden urges. The man returned to a normal life but years later started collecting child pornography. An MRI revealed the tumor had grown back. When it was removed for the second time, the man returned to normal.