James Holmes, the 24-year-old man accused of opening firing in an Aurora, Colorado movie theater, was formally charged Monday with 24 counts of 1st degree murder and 116 counts of attempted murder.

PHOTOS: Stars gone too soon

According to ABC News, the alleged gunman appeared in Aurora District Court to hear his charges. Holmes is accused of killing 12 people and wounding 58 after he allegedly opened fire in a midnight showing of The Dark Knight Rises.

He faces a total of 142 criminal charges including, one count of possessing an explosive device and one count of a violent crime.

PHOTOS: The Dark Knight Rises movie stills

"I don't think it's too hard to predict the path of this proceeding," Craig Silverman, a former chief deputy district attorney in Denver told CBS News. "This is not a whodunit. ... The only possible defense is insanity."

Holmes, who identified himself to police as Batman villain "The Joker" at the time of his arrest, still had his hair dyed orange in court. He only spoke once when the judge asked if he wanted to waive his right to preliminary hearing within 30 days, saying, "Yes."

PHOTOS: Stars in court

If convicted, Holmes could face the death penalty.

This article originally appeared on Usmagazine.com: James Holmes Charged With 24 Counts of Murder in Dark Knight Rises Massacre