James Holmes wants to plead not guilty by reason of insanity to the killing of 12 people and the wounding of 58 others in the Aurora, Colo., movie theater attack.
In a filing Tuesday, Holmes' lawyers wrote they intend to "tender a plea of not guilty by reason of insanity." Holmes would need the judge's permission to change his plea.
The notice filed Tuesday starts a series of dominoes in the case.
Because a judge entered a standard not guilty plea on behalf of Holmes — and over the objection of Holmes' attorneys — at arraignment, Holmes' attorneys will have to show "good cause" why they should be allowed to change the plea to insanity.
If the plea change is allowed, the judge will immediately order Holmes to undergo an independent mental-health evaluation — something that could potentially take months.
Meanwhile, Holmes' lawyers will now likely re-submit their complaints that Colorado's system for insanity pleas in death-penalty cases is unconstitutional. They have previously argued, for instance, that requiring Holmes to participate in the mental-health evaluation would violate his rights against self-incrimination. The judges overseeing the case, though, rejected those arguments at the time because Holmes hadn't yet actually pleaded insanity.
In the notice Tuesday, Holmes' lawyers write they made the filing, "[w]hile maintaining all previous objections and arguments regarding the constitutionality" of the insanity-plea laws.
Holmes is charged with 166 counts of murder, attempted murder and other offenses for the July 20 attack on the Century Aurora 16 movie theater. His attorneys have previously hinted that Holmes' mental illness would feature prominently in his defense.
"[T]he reason the defense is considering entering an (insanity) plea is because Mr. Holmes suffers from a serious mental illness," his lawyers wrote in a motion filed late last month.
Shooting survivors and family members of victims, however, have said they are suspicious of Holmes' claims of mental illness, citing, for instance, the detailed planning Holmes allegedly put into the attack.
"He's a hollow person, very evil," Jessica Watts, the cousin of slain theater victim Jonathan Blunk, said after Holmes' arraignment in March. "He's absolutely not insane. ... Just, he doesn't seem like he does a whole lot to help himself. He doesn't seem real interested in what's going on in his own future."