'Dark Knight Rises' Shooting: James Holmes Expected to Be Formally Charged Monday

James Holmes is expected to be formally charged Monday in the murder of 12 people at a July 20 screening of The Dark Knight Rises.

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Holmes is suspected of killing 12 people and wounding 58 others during a midnight showing of the movie at a theater in Aurora, Colo. He is reportedly facing 12 counts of first-degree murder charges, according to court documents.

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Holmes made his first court appearance July 23, where he remained silent and emotionless, mostly looking down or away from the proceedings. The former doctoral student, who is being represented by a public defender, appeared in court with his hair dyed a reddish-orange. At times, his face morphed from a blank stare to bulging and wide-eyed, prompting reporters to ask attorneys if he had been drugged. 

Holmes was advised of his rights but no plea was entered.

"We are still looking at an enormous amount of evidence," said Carol Chambers, the Eighteenth Judicial District Attorney, on Monday. "It's still a very active, ongoing investigation."

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Chambers added that Holmes could face the death penalty, but attorneys are planning to consult with victims' families before making a decision.

After the shooting, authorities searched Holmes' apartment, which they found booby-trapped with numerous explosives.

Ten survivors remain hospitalized Sunday, with four in critical condition, CNN reported.

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Holmes is being held, without bond, in isolation at the Arapahoe County Jail.

Formal filing of charges is expected at 9:30 a.m. Monday.

Sheba Wheeler contributed to this report.