The insanity defense will make the trial difficult for the prosecution because, in contrast to the vast majority of states, Colorado puts the burden of proof on the prosecution, rather than on the defense. That means prosecutors will have to prove that Holmes is not insane, which could be an arduous task in a case involving so many unusual variables, such as Holmes’ bomb-rigged apartment, his orange-dyed hair, reports he told the police he was the cartoon villain the Joker, his heavy reliance on a psychiatrist and prescription medicine, and so forth.
Even faced with that task, however, the prosecution will not have a difficult case in proving Holmes knew what he was doing, says Daniel Filler, a former public defender who teaches criminal law at Drexel University School of Law in Philadelphia.
“While formally the burden of proof is on the prosecution, the reality is that juries are not typically very sympathetic to insanity claims,” Professor Filler says. “It is important to distinguish the formal rules of law and what the practical challenges are. The reality is the prosecution has the winds at its back in arguing [Holmes] is not insane because, after a horrible crime, juries are not looking for a way to absolve the defendant.”
The trial will ultimately come down to “a battle of experts,” he adds.