james holmes
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James Holmes
A computer, homemade explosives, a Batman mask and other Batman paraphernalia seized at the Colorado apartment of James Holmes could help shed light on the mind, motive and modus operandi of the mass killing suspect, a federal law enforcement official said Sunday.

Holmes is being held without bond on suspicion of multiple counts of first-degree murder after a shooting rampage minutes into a premiere of The Dark Knight Rises early Friday that left 12 people dead and 58 wounded. He is scheduled for an initial hearing this morning, and has been assigned a public defender.

The federal official, who is not authorized to comment publicly, said the computer could aid the effort to determine how long the suspect might have been planning the attack and other details of the massacre.

In addition to the physical evidence, a picture of the suspect is emerging from his encounters with others. Last month, he applied to join a Colorado gun range but never became a member because of his behavior and a "bizarre" message on his voice mail greeting, the range's owner said Sunday.

Holmes, 24, e-mailed an application to join the Lead Valley Range in Byers on June 25 in which he said he was not a user of illegal drugs or a convicted felon, said owner Glenn Rotkovich.

But when Rotkovich called to invite him to a mandatory orientation the following week, he said he heard Holmes' voice mail greeting that was "bizarre -- guttural, freakish at best."

It identified the number as belonging to "James," so Rotkovich said he left a message.

He left two other messages but told his staff to watch out for Holmes at the July 1 orientation and not to accept him into the club, Rotkovich said. His comments were first reported by Fox News.

"There's something weird here," Rotkovich said he concluded.

Aurora Police Chief Dan Oates said Sunday that Holmes has "lawyered up" and is not talking.

Oates said it could take months to determine a motive, and police are working with FBI behavioral analysts.

The police chief said Holmes had more than 50 commercial packages delivered to his home and school address during the last four months.

A maze of incendiary devices arrayed inside Holmes' apartment included 10 gallons of gasoline likely intended to serve as an accelerant to any fire caused by an explosion inside, the official said.

The devices included about 30 aerial shells commonly used in commercial fireworks displays.

The official said the shells had been cannibalized, reconstructed and set up in the living room, where a stream of wires connected them to a "control box" in the unit's kitchen. The box was successfully disabled Saturday by bomb technicians using robotic devices and a controlled detonating device.

Had the devices detonated as planned, the official said, the explosion and gasoline would have created a fireball that would have likely consumed the apartment and perhaps much of the building's top floor.

Also Sunday, the University of Colorado said it is investigating whether Holmes used his position as a graduate student at its Denver campus to order materials for the potentially deadly booby traps.

Police said Holmes received deliveries over four months to his Aurora, Colo., apartment and the school. They haven't identified the contents. University spokeswoman Jacque Montgomery said the school is looking into those packages received at the school.

The latest information represents more pieces to a puzzle that authorities are constructing to determine what was happening inside the mind of the quiet, intellectually gifted neuroscience student suspected of morphing into a vicious killer.

In Rancho Peñasquitos, a community of picturesque, hacienda-style homes surrounded by hills and canyons outside San Diego where Holmes grew up, residents have a hard time squaring the quiet teen who didn't call attention to himself with the image of Holmes emerging now.

Those who knew Holmes in the upscale community remember a polite young man who kept to himself and excelled academically.

Today, Aurora police portray Holmes as a suspect intent on killing, taking the violence even further by booby-trapping his apartment to kill the first person to enter, most likely a police officer.

In the six months before the shooting, police said Holmes bought at least 6,000 rounds of ammunition, an AR15 assault rifle, a Remington shotgun and two 40-caliber Glock handguns. He bought them legally, according to a federal law enforcement official who was not authorized to speak publicly.

Oates said Holmes used a rifle, shotgun and one of the handguns during the attack.

Holmes seems to have little online presence. Unlike many people his age, he does not have accounts on Twitter, Facebook or other social media.

He did, however, turn to the Internet to meet women. He created a profile on AdultFriendFinder.com, a dating and sex chat website, said a law enforcement official who wasn't authorized to speak publicly and requested anonymity.

His photo showed a man with orange hair who called himself "classicjimbo." He said he was "looking for a fling or casual sex gal," according to the Washington Post. In another part of the post, which has since been taken down, he asked: "Will you visit me in prison?"