A gunman accused of killing seven people at a Christian college was an angry loner who hated women, had been fired from his job and felt overshadowed by his Iraq war veteran brother.
New details about One Goh, 43, a Korean-American nursing student, were disclosed as detectives released the first photograph of him, staring blankly into a camera hours after Monday's mass shooting in Oakland, California.
Romie John Delariman, a college teacher who knew Goh, said he was a keen student but felt paranoid about being an older man in classes where most pupils were young women. Six of those who died in the massacre were women and the only man to die was shot by Goh in a carjacking as he fled from the scene.
Mr Delariman said: "He said he was too old to go to school with all the young people and he said all his classmates were mean to him. He just can't deal with women. I always advised him, 'You go to school to learn, not to make friends'. He can't get along with people. If you say 'How are you?' he'll say 'Why? Don't I look OK? Did I do something to you?'"
The teacher said Goh had also boasted about beating up a mugger in San Francisco and talked about carrying a gun for protection. "I don't know if you could call it mentally unstable but sometimes he would brag that he was capable of hurting people," he added.
Goh had been expelled from Oikos University, a small 100-student religious education establishment, in January for "anger management" issues. He bought a semi-automatic pistol legally the following month.
For most of the previous decade he had lived in Virginia, the state where a gunman killed 32 innocent people at the Virginia Tech campus in 2007. While in that state, Goh incurred debts including $23,000 (pounds 14,500) in unpaid taxes and $15,000 (pounds 9,500) to banks.
After arriving in California to make a new start, he described leaving behind a divorce, a daughter, and a failed building business in Virginia. He found a job at an Asian food warehouse but was sacked after four months for arguing with customers. The death of his war veteran brother in a road accident last year was said to have affected him deeply.
On Tuesday night 1,000 people gathered for a memorial service at a Baptist church in Oakland.
Mayor Jean Quan, the first Asian-American woman mayor of a major US city, told mourners: "This is America, where you can find a gun easier than mental health services. America has to look into its soul. It cannot be that we can find more guns in our streets than we can find health care and mental health services."
