James Holmes, the former neuroscience graduate student suspected of killing 12 people and wounding dozens more during a July 20 shooting rampage at a movie theater in Aurora, CO, has been formally charged with 24 counts of murder and 116 counts of attempted murder.

Colorado prosecutors entered the charges on Monday, a little more than two weeks after they say Holmes, 24, went on a shooting spree during a midnight showing of ‘The Dark Knight Rises.’ After his arrest, police discovered his apartment was booby-trapped, so Holmes was also charged with one count of possession of explosives.

He was in court for Monday’s hearing and security was tight, with armed officers on rooftops in the court complex and law enforcement vehicles blocking building entrances.

Legal analysts predict the case will be dominated by arguments over Holmes’ sanity.

“I don’t think it’s too hard to predict the path of this proceeding,” said Craig Silverman, a former chief deputy district attorney in Denver. “This is not a whodunit….The only possible defense is insanity.”

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