Imagine being the prosecutor tasked with disproving—beyond any reasonable doubt—the insanity of someone like James Holmes. How would you explain Holmes reportedly telling police he was the Joker? Or why he showed up to court with dyed orange hair and behaved so strangely? Notebooks full of violent plots, bottles of prescription medication retrieved from his apartment, and an attempt to call his psychiatrist just minutes before the shooting ... you'd have your work cut out for you trying to convince jurors that the defendant was perfectly sane when he entered the Century 16 movie theater.

It would be especially hard to demonstrate Holmes's sanity because Colorado has a hybrid way of establishing legal insanity. Colorado, like many states, follows the M'Naghten rule. This test basically determines whether or not the defendant knew what they were doing was wrong at the time of the crime. This means that if the defense can establish Holmes was unaware of the fact that his actions were wrong, he could enter an insanity plea. But even if he fully knew what he was doing was wrong, he could still claim insanity under Colorado's other criteria—the irresistible impulse. This holds that even if Holmes knew his actions were wrong, he could still be considered insane if he was unable to stop himself from carrying them out.

However, Holmes's team does not have a slam-dunk insanity case—not by any means. Former president of the National Association of Criminal Defense Lawyers Lisa Wayne tells Voice of America that while defense attorneys in Colorado don't have to shoulder the burden of proof in an insanity case, they do have an uphill climb in presenting credible evidence for entering an insanity plea in the first place:

Can we show that, in fact, this is someone who really was planning and there was premeditation and those kind[s] of things? Or is there really a likelihood that this person has a mental disease or defect? ... The mental health part of it is very important in terms of lining up credible psychiatrists, doctors who can really, in a credible fashion, say this defendant is just suffering from an extreme mental illness.

On top of that, the University of Colorado, Denver psychiatrist Holmes met with—and who reported concerns to campus police—may not be able to testify due to the doctor-patient privilege. Even with the loss of that witness, the defense's case if they choose to pursue an insanity defense seems strong under Colorado law.

This article is from the archive of our partner The Wire.