Neighbors at a sprawling apartment complex in Torrance said they thought it was odd when a few years ago they saw Chris Harper Mercer and his mother carrying black cases that the neighbors suspected held firearms.
At a community barbecue, some asked Mercer whether he owned guns. Mercer deflected the question but acknowledged that he liked to practice target shooting, said David Westly, 45.
Neighbors at the Arlington Avenue complex were left to wonder Thursday whether that memory is one piece of a larger puzzle after Mercer, 26, was identified by law enforcement sources as the gunman who went on a rampage at an Oregon community college that left 10 dead, including Mercer.
"It's hard to believe," Westly said.
Resident Derrick McClendon, 42, agreed.
"I wouldn't have suspected him to be a troubled person," he said. "I'm surprised and shocked, I really am."
A MySpace profile identified as Chris Harper Mercer from Torrance showed a young man with a shaved head and the barrel of a rifle pointing up into the frame of his portrait.
Another photo on the account shows him wearing a suit.
Within a few hours of the shooting, FBI agents in Los Angeles fanned out to interview those who knew Mercer from his time in Torrance to help build a fuller profile of his history, beliefs and prior behavior, according to a law enforcement source familiar with the probe.
An FBI agent was interviewing Mercer's father, Ian Mercer, at his Tarzana home Thursday evening when a TV news truck pulled up outside.
Later that evening, Ian Mercer briefly stepped outside his home and told reporters he had spent the day speaking with police and other authorities.
He said he couldn't answer any questions about his son or the shooting.
"Shocked is all I can say," he told reporters. "It's been a devastating day."
Another relative, who asked not to be identified, said Chris Harper Mercer lived with his mother in the Los Angeles area for "most of his life", and that they had recently moved to Oregon.
The relative described Mercer as "quiet." She said that he joined the Army at one point, but that she did not know any details or why he left.
Mercer was among five students listed in the graduating class at Switzer Learning Center, according to a special graduation section published by the Torrance-based newspaper, the Daily Breeze, in 2009.
The Switzer Learning Center, also in Torrance, teaches students with special needs, emotional disturbances, autism, Asperger's syndrome and other issues. According to its website, the school "has a long history of working with children who have been unsuccessful in traditional classrooms because they need the special attention and encouragement that only a school like Switzer can provide."
A dating website profile that bears Mercer's name and photo describes him as "conservative, professional, intellectual, introvert ... Not Religious, but Spiritual." It's unclear when the profile was written but says Mercer was attending college and is "shy at first, but warm up quickly, better in small groups."
Neighbors in Torrance said Mercer and his mother largely kept to themselves. Mercer's mother sometimes got involved in community disputes, such as complaints about loud noises, they said, and once circulated a petition to get the apartment owner to eradicate a cockroach infestation. Neighbors said she told them the insects kept her son awake at night.
"She would go around knocking on neighbor's doors," said Rosario Lucumi, 51. "She would call him 'baby' all the time. I thought it was strange because he was an adult."
Lucumi and her daughter, Rosario Espinoza, 33, said Mercer often seemed unsettled.
"He was always moving around," Lucumi said.
"It's like he was always anxious or nervous," Espinoza added.
They sometimes saw him taking the bus, but that he didn't want to talk, they said.
McClendon said Mercer was a bit of a loner. "I never saw him with friends or a girlfriend," he said. "He was bashful and timid."
Others said Mercer would ride around the area on a red beach cruiser bike, sometimes dressed in military-style green pants tucked into black boots.
Before they moved, the mother gave Mercer's bike to a teenage neighbor.
"She said, 'Chris wants to give you his bike,'" recalled Bryan Clay, who was given the cruiser. "Looking back now, I think it was strange. I didn't really know them."
Staff writers Stephen Ceasar, Angel Jennings and Sarah Parvini contributed to this report.