CENTENNIAL, Colo. (AP) - The judge in the deadly Colorado shooting case has entered a not guilty on behalf of James Holmes after his lawyer said he's not ready to enter a plea.
The judge says Holmes can change his plea to not guilty by reason of insanity later, if he chooses.
If convicted, Holmes could be executed or spend the rest of his life in prison.
Holmes is charged with multiple counts of murder and attempted murder. Twelve people were killed and 70 wounded in the July 20 attack on moviegoers in Aurora.
Pleading insanity could be the only way he can avoid life in prison or execution, given the evidence that has emerged so far, some legal experts said.
Prosecutors laid out a case that Holmes methodically planned the shooting for months, amassing an arsenal and elaborately booby-trapping his apartment to kill anyone who tried to enter. On the night of the attack, they say, he donned a police-style helmet, gas mask and body armor, tossed a gas canister into the seats and then opened fire.
"This is not a whodunit," criminal defense attorney Dan Recht said in January. He is not involved in the case.
Holmes is charged with 166 counts, mostly murder and attempted murder, in the July 20 assault on moviegoers at a midnight showing of "The Dark Knight Rises" in Aurora, a Denver suburb.
If a jury agrees he was insane, he would be committed indefinitely to a state mental hospital. There would be a remote and unlikely chance he could be freed one day if doctors find his sanity has been restored.
The plea carries risk, however. Prosecutors would gain access to Holmes' mental health records, which could help their case if the evidence of insanity is weak. If Holmes does plead insanity, the proceedings would be prolonged further while he is evaluated by state mental health officials.
"You heard the evidence they have. There is no doubt that he knew what he was doing was wrong, there's no doubt it was premeditated," said Tom Teves of Phoenix, whose 24-year-old son, Alex, died in the theater while shielding his girlfriend. "There's no doubt he did it. Zero. So why are we playing a lot of games?"
Holmes could also plead innocent - not by reason of insanity - which would significantly change the court fight. Prosecutors would not have those medical records, but Holmes could be convicted outright, with a possible life term or death.
No matter how Holmes pleads, he could still be convicted and sentenced to execution or life in prison without parole. Prosecutors have 60 days after the plea to say whether they will seek the death penalty.
The hard-fought case has already taken some surprise turns, and Tuesday's hearing could offer another unforeseen twist, including the remote possibility the two sides, ordered by the judge to not speak publicly about the case, have reached a plea agreement.
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