James Holmes, 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.

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

Said Craig Silverman, a former chief deputy district attorney in Denver, “This is not a whodunit….The only possible defense is insanity.”