Updated

The 24-year-old man who police say walked into a Colorado movie theater and sprayed patrons with gunfire is a grad school dropout who grew up in San Diego and had only one known brush with the law — a traffic ticket last year.

Tall and dark-haired, James Egan Holmes stared clear-eyed at the camera in a 2004 high school yearbook snapshot, wearing a white junior varsity soccer uniform -- No. 16. The son of a nurse, Arlene, and a software company manager, Robert, James Holmes was a brilliant science scholar in college.

But Friday morning just past midnight, police say Holmes burst into the crowded Century 16 movie theaters in Aurora, Colo., where the Batman movie “The Dark Knight Returns” was being shown and opened fire with three guns, killing at least 12 and injuring scores.

What snapped in the neuroscience student’s brain is unclear. Jackie Mitchell, a furniture mover who lives several blocks from the suspect's apartment building in Colorado, said he had drinks with Holmes at a local bar on Tuesday night, though he gave no sign of being distressed or violent.

After Holmes approached him "we just talked about football. He had a backpack and geeky glasses and seemed like a real intelligent guy, and I figured he was one of the college students," Mitchell said.

More On This...

When Mitchell saw Holmes' photo after the shooting, "the hair stood up on my back," he said. "I know this guy."

Mitchell also said Holmes seemed smart, with a "swagger."

Holmes, who stands 6-foot-3, graduated from San Diego’s Westview High School in 2006, Poway Unified School District confirmed to Fox News. A gifted student, he studied neuroscience at nearby University of California-Riverside, where he graduated in 2010 with highest honors.

But in the age of widespread social media, no trace of Holmes could be found on Facebook, LinkedIn, MySpace, Twitter or anywhere on the web. Either he never engaged or he scrubbed his trail.

Anthony Mai, a 16-year-old who grew up next door to Holmes, described Holmes as a "solitary" person who largely kept to himself but his behavior was nothing out of the ordinary.

"He felt a little bit concealed, but it wasn't too much. It was alright" he said. "This is just a feeling in my gut, but I felt like he had something, like he was being picked on or something."

His father, Tom Mai, a retired electrical engineer, said Holmes was quiet.

"I said hello to him once in a while. He seemed to be a shy guy," he told reporters.

The bookish demeanor concealed an unspooling life. Holmes struggled to find work after graduating college, Tom Mai said.

Holmes enrolled last year in a neuroscience Ph.D. program at the University of Colorado-Denver but was in the process of withdrawing, said school officials, who didn't provide a reason.

As part of the advanced program in Denver, a James Holmes had been listed as making a presentation in May about Micro DNA Biomarkers in a class named "Biological Basis of Psychiatric and Neurological Disorders."

In academic achievement "he was at the top of the top," recalled Riverside Chancellor Timothy P. White.

Holmes concentrated his study on "how we all behave," White added. "It's ironic and sad."

Holmes described himself last year in an apartment rental application as "quiet and easy going," the Denver Post reports.

Holmes, who is in police custody and is reportedly no longer cooperating with authorities, appears to have meticulously planned the horrific attack, booby-trapping his apartment near the Aurora, Colo., with what police described as "incendiary and chemical devices" equipped with sophisticated tripwires. At the cinema, he entered through a fire door he’d previously left open and then set off some sort of explosive before opening fire with multiple guns, including an AR-15 assault rifle, a shotgun and at least one .40-caliber Glock handgun.

Holmes, who was dressed in black and wearing a protective vest, was arrested by his car outside the movie theater minutes after the attack. Holmes did not resist cops and reportedly told them his apartment — just four miles from the theater and within view of Children's Hospital, where some of his victims were taken — was rigged to kill.

Police say the attack is not tied to terrorism and have thus far have provided no motive. Holmes' only known brush with authorities was a speeding ticket issued last October. Federal law enforcement sources told USA Today Holmes "was not on anybody's radar."

Julie Adams, whose son played junior varsity soccer with Holmes, said her son remembered little about the suspect, which was unusual for the tight-knit team.

"I don't think many of the kids (teammates) knew him. He was kind of a loner," she said.

When he surrendered meekly in the movie house parking lot, Holmes told authorities what he'd done at his residence in the Denver suburb of Aurora, the third most populous city in Colorado.

"Our hearts go out to those who were involved in this tragedy and to the families and friends of those involved," Holmes' family said in a written statement Friday. "We ask that the media respect our privacy during this difficult time."

On Friday morning, police escorted the suspect's father from the family's San Diego home. The mother stayed inside, receiving visitors who came to offer support.

San Diego police spokeswoman Lt. Andra Brown, spoke to reporters in the driveway of the Holmes' home, on behalf of the family.

"As you can understand, the Holmes family is very upset about all of this," she said. "It's a tragic event and it's taken everyone by surprise."

The Associated Press contributed to this report.