CENTENNIAL, Colo. (AP) -- Colorado prosecutors have formally charged a former doctorate student with 24 counts of murder in the shooting at an Aurora movie theater.
Twenty-four-year-old James Holmes appeared Monday and was also formally charged with 116 counts of attempted murder.
Twelve people were killed and 58 people were wounded or injured. According to reports, there are 24 murder counts because, for each of the 12 victims killed, prosecutors filed a charge of First Degree Murder and also an additional charge of First Degree Murder with Extreme Indifference. The maximum penalty is death.
Holmes is also charged with a one count of possession of explosives. Authorities say he booby trapped his apartment.
Holmes was arrested early July 20 outside a Century 16 theater in Aurora during a midnight showing of the new Batman movie.
Legal analysts expect his court the case to be dominated by arguments over his sanity.
Holmes was a student at the University of Colorado Denver before withdrawing last month
Authorities seized the package July 23, three days after the shooting, after finding it in the mailroom of the medical campus where Holmes studied. Several media outlets reported that it contained a notebook with descriptions of an attack, but Arapahoe County District Attorney Carol Chambers said in court papers that the parcel hadn't been opened by the time the "inaccurate" news reports appeared.
Holmes allegedly began stockpiling gear for his assault four months ago, and authorities say he bought his weapons in May and June, well before the shooting spree just after midnight during a showing of the Batman film ""The Dark Knight Rises." He was arrested by police outside the theater.
Analysts say that means it's likely there's only one main point of legal dispute between prosecutors and the defense.
"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.”
Under Colorado law, defendants are not legally liable for their acts if their minds are so "diseased" that they cannot distinguish between right and wrong. However, the law warns that "care should be taken not to confuse such mental disease or defect with moral obliquity, mental depravity, or passion growing out of anger, revenge, hatred, or other motives, and kindred evil conditions.”
Experts say there are two levels of insanity defenses. Holmes' public defenders could argue he is not mentally competent to stand trial, like Jared Loughner, who killed six people when he shot Arizona Rep. Gabrielle Giffords in Tucson in 2011. Loughner has pleaded not guilty to charges in the shooting. He has been diagnosed with schizophrenia and is undergoing treatment at a Missouri prison facility in a bid to make him mentally fit to stand trial.
If Holmes' attorneys cannot convince the court that he is mentally incompetent, and he is convicted, they can try to stave off a possible death penalty by arguing he is mentally ill. Prosecutors will decide whether to seek the death penalty in the coming weeks.
Holmes was not expected to enter pleas on Monday.
Holmes ultimately could enter a plea to the anticipated dozen first-degree murder charges verbally, or his attorneys could enter it for him. Prosecutors may file multiple counts of attempted first-degree murder and other charges against Holmes, whom Aurora police say booby-trapped his apartment with the intent to kill any officers responding there the night of the theater attack.
A woman who was critically wounded and whose 6-year-old daughter was killed suffered a miscarriage, her family said Saturday. The family of Ashley Moser said the trauma caused the miscarriage. Moser's daughter, Veronica Moser-Sullivan, was the youngest person killed in the attack.
Sam Kamin, a law professor at the University of Denver, said there is "pronounced" evidence that the attack was premeditated, which would seem to make an insanity defense difficult. "But," he said, "the things that we don't know are what this case is going to hinge on, and that's his mental state.”
With an unruly mop of orange hair, Holmes appeared bleary-eyed and distracted during his brief initial appearance in court last week. He did not speak.
Friends in Southern California, where Holmes grew up, describe him as a smart, sometimes awkward youth fascinated by science. He came to Colorado's competitive neuroscience doctoral program in June 2011. A year later, he dropped out shortly after taking his year-end exam.
District Court Judge William Blair Sylvester has tried to tightly control the flow of information about Holmes, placing a gag order on lawyers and law enforcement, sealing the court file and barring the university from releasing public records relating to Holmes' year there. A consortium of media organizations, including The Associated Press, is challenging Sylvester's sealing of the court file.
On Friday, court papers revealed that Holmes was seeing a psychiatrist at the university. But they did not say how long he was seeing Dr. Lynne Fenton and if it was for a mental illness or another problem.
The University of Colorado's website identified Fenton as the medical director of the school's Student Mental Health Services. An online resume listed schizophrenia as one of her research interests and stated that she sees 10 to 15 graduate students a week for medication and psychotherapy, as well as 5 to 10 patients in her general practice as a psychiatrist.
Authorities say Holmes legally purchased four guns before the attack at Denver-area sporting goods stores -- a semiautomatic rifle, a shotgun and two pistols. To buy the guns, Holmes had to pass background checks that can take as little as 20 minutes in Colorado.