By Sara Zhang | WIRED | August 3, 2015
JAMES HOLMES WALKED into a midnight screening of The Dark Knight Rises in 2012 carrying three guns including a semi-automatic rifle and opened fire, killing 12 people and injuring 70 more. Nobody, not even his defense attorneys, denied that. But those attorneys still told a jury and a judge that Holmes was not guilty of those crimes—because he was insane. Last month, that jury rejected that assertion, finding Holmes guilty on all counts.
Holmes’ plea didn’t get him off, but it did get people talking about the insanity defense again. It’s a rare move for defense attorneys these days, even quaint sounding. Psychiatrists no longer call patients “insane.” It’s not a clinical diagnosis. Yet the term persists in the courtroom—along with many other practices unsupported by modern psychology and neuroscience.
Americans inherited a legal system shaped by history, not by science. “The legal system is resistant to change and resistant to paying attention to scientific research,” says Adam Benforado, a law professor at Drexel University and author of the recent book Unfair: The New Science of Criminal Injustice. The system assumes that innocent people don’t confess to crimes they didn’t commit. It presumes that eyewitness testimonies are reliable. It counts on the impartiality of jurors.
None of those things are borne out by evidence.