updated 07/20/2012 AT 2:40 PM ET
•originally published 07/20/2012 AT 3:00 PM ET
James Holmes, the alleged gunman who killed 12 people and injured dozens during a screening of the Batman movie The Dark Knight Rises, described himself as the hero’s arch nemesis, a police official says.
“It clearly looks like a deranged individual. He had his hair painted red, he said he was ‘The Joker,’ obviously the enemy of Batman,” New York Police Commissioner Ray Kelly said Friday at a press conference.
The source of Kelly’s information wasn’t immediately clear – also, The Joker had green hair.
However, the commissioner is reportedly a close friend of Dan Oates, the chief of police in Aurora, Colo., where the massacre occurred. Oates, formerly a longtime member of the New York Police Department, didn’t confirm or deny The Joker account, but did say he had spoken with Kelly.
Two federal law enforcement officials confirmed to ABC News the details of The Joker costume.
In a separate news conference in Aurora, Oates declined to speculate on a motive. He said that Holmes was believed to be the only suspect, armed with an assault rifle, shotgun and handgun as he opened fire on the packed movie house.
A total of 71 moviegoers were shot at the Century 16 Theater at the Town Center Mall, including one person in another theater by a bullet that went through the wall.
Police responded quickly and Holmes was arrested without significant incident, but his nearby apartment was heavily booby-trapped with trip wires and explosives, says Oates.
Holmes, 24, had no criminal record besides a traffic summons in October 2011. He went to high school in San Diego and withdrew from Colorado University, where he had been studying for his PhD in neuroscience since fall 2011.
Upon learning of the shooting, Holmes’s mother, who lives in San Diego, confirmed to ABC News that her son was the shooter, based on her instinct, saying “You have the right person.”
Later, Police Lt. Andra Brown in San Diego read a written statement from the Holmes family:
“Our hearts go out to those who were involved in this tragedy and to the families and friends of those involved. We ask that the media respect our privacy during this difficult time. Our family is cooperating with authorities in both San Diego, California, and Aurora, Colorado. We are still trying to process this information and we appreciate that people will respect our privacy.”
A man identified by police as Holmes’s father left the San Diego home with law enforcement Friday morning, while his mother remained inside with other family members and friends who have come by offering support, Brown said.