The man arrested in connection with the massacre at a Colorado movie theatre is a shy, intelligent person raised in California by parents who were active in their well-to-do suburban neighbourhood, those who know him say.

James Holmes, 24, who was studying neuroscience in a Ph.D. program in Colorado, grew up in San Diego, where his parents still live on a quiet street, of two-storey homes with red tile roofs. He played soccer at Westview High School and ran cross-country before going to college.

James Holmes had a master's degree from a California university but had been unable to find a job. (Reuters/University of Colorado)

Neighbours say the family belonged to a Presbyterian church and hosted a Christmas party for residents. Many families choose the San Diego neighbourhood because it is part of the well-regarded Poway Unified School District, one of the best in California.

On Friday morning, police escorted the suspect's father, a manager of a software company, from his San Diego home. The mother, a nurse, stayed inside, receiving visitors who came to offer support. The suspect also has a younger sister.

"As you can understand, the Holmes family is very upset about all of this," San Diego police spokeswoman Lt. Andra Brown, told reporters in the driveway of the family's home. "It's a tragic event and it's taken everyone by surprise. They are definitely trying to work through this."

The family in a written statement said "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."

There have been no indications so far that Holmes had any run-ins with the law before Friday. San Diego Superior Court spokeswoman Karen Dalton said there were no records found under his name, not even for a traffic ticket. Riverside County prosecutors also have no criminal record for him, said John Hall, a spokesman for the district attorney's office.

A furniture mover who lives several blocks from the suspect's Aurora apartment building said he shared a beer with Holmes Tuesday at a neighbourhood bar where they talked about Denver Bronco quarterback Peyton Manning.

Smart with a 'swagger'

Jackie Mitchell said he recognized Holmes's photo on television as the guy he met at the bar. He described him as smart with a "swagger."

"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," he said.

There was no reference made to a planned shooting, Mitchell said.

Anthony Mai, 16, who grew up next door to Holmes, said the suspect largely kept to himself but his behaviour was nothing out of the ordinary.

"He felt a little bit concealed, but it wasn't too much. It was all right," 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 a "shy guy" who came from a "very, very nice family."

Rose To said the Holmes family set up chairs in their garage for a Christmas party a few years ago, giving neighbours a chance to mingle.

"They were really nice people, good neighbours," she said.

Mai said the mother told him the suspect couldn't find a job after earning a master's degree from a University of California school and so went back for another degree.

Holmes graduated from University of California, Riverside, in the spring of 2010 with a bachelor of science degree in neuroscience, said university spokesman Sean Nealon. No other details were immediately available about his life on campus, Nealon said.

In 2011, Holmes enrolled in the Ph.D. neuroscience program at the University of Colorado-Denver but was in the process of withdrawing, said spokeswoman Jacque Montgomery. University officials earlier said he was a student at the university's medical school.