James Holmes, the man accused of killing 12 people and injuring 70 others in an Aurora, Colo., movie theater intends to plead not guilty by reason of insanity. Rick Salinger reports.

CENTENNIAL, Colo. -- James E. Holmes, suspected of carrying out the Aurora movie theater massacre that killed 12 and injured 70 last summer, will plead not guilty by reason of insanity in court next week, his defense lawyers signaled Tuesday in a court filing.

The defense decision has long been anticipated as Holmes’ lawyers have repeatedly described him as “severely mentally ill.” But no matter how expected, the latest development has been many months in coming amid intense legal wrangling over the constitutionality of the Colorado insanity defense.

Last month, a visibly annoyed Judge William Sylvester of Colorado’s 18th Judicial District entered a traditional not guilty plea on Holmes’ behalf after defense attorneys said they were not ready to make a decision. Sylvester told defense lawyers they could change the plea to not guilty by reason of insanity at a later date but would have to show cause.

Since then Sylvester has stepped aside and been replaced by Judge Carlos A. Samour Jr.

Holmes is charged with 166 counts of first-degree murder, attempted murder and weapons charges for the July 20 rampage. He is accused of opening fire during a packed premiere of “The Dark Night Rises.” He faces the death penalty if found guilty.

But by law he cannot be put to death if he is deemed insane or suffering a mental defect.

Defense attorneys said in a court filing in March that they had offered to let Holmes plead guilty without the possibility of parole if the district attorney’s office dropped the death penalty. That offer was rejected, and on April 1, Dist. Atty. George Brauchler announced in court that “justice is death” for Holmes.

The change of plea will occur at a scheduled pretrial hearing at 9 a.m. Monday.

Once the change of plea is officially entered, the clock will begin ticking for Holmes to undergo extensive psychiatric evaluation at a state hospital. Often misunderstood, an insanity plea does not mean a defendant did not plan a crime or show premeditation, but instead refers to his mental state at the moment of the crime.

The defense on Tuesday renewed its previous constitutional challenges to that process. Previously, the defense has argued unsuccessfully that Holmes’ rights could be violated under Colorado laws governing insanity pleas by denying him due process if he does not cooperate with the psychiatric evaluations.

Trial is scheduled for February 2014, but legal experts have said that the combination of the death penalty and an insanity plea could add months, if not years, to the process.

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