One L. Goh, 43, forced the secretary into a classroom at Oikos University in Oakland on Monday, told people to line up and, when some didn't cooperate, began his shooting spree, police Chief Howard Jordan said.
"It's very, very sad," Jordan said. "We have seven people who didn't deserve to die and three others wounded because someone who couldn't deal with the pressures of life."
Goh, a South Korea native who became a U.S. citizen, was expelled in January from the school for behavioral problems from the small private school of fewer than 100 students, Jordan said. The chief said Goh had anger management issues with other students.
Jordan said Goh appeared to have been planning the attack for several weeks.
Goh was upset with administrators and several students at the college, which an official said offered classes in Korean and English and was founded to help Korean immigrants adjust to a new country and find careers in nursing and ministry.
"They disrespected him, laughed at him," Jordan said. "They made fun of his lack of English speaking skills. It made him feel isolated compared to the other students."
Jordan said Goh tried to find a female administrator Monday and began shooting when he learned she wasn't there. The victims, who range in age from 21 to 40, were from various countries, including Nigeria, Nepal and the Philippines.
"It is very disturbing, especially given the magnitude of this incident," he said. "While he's being very cooperative with us, you expect some level of remorse for someone who just killed seven people that he really didn't even know."
Goh was being held without bail Tuesday after being booked on suspicion of murder, attempted murder, kidnapping and carjacking, according to sheriff's Sgt. J.D. Nelson, who said the suspect likely would make his first court appearance Wednesday.
Police were still looking for the gun used, which Jordan described as a semiautomatic handgun that was purchased legally.
Goh has no criminal history, but he has debts and minor traffic citations in his former home state of Virginia and was evicted from one apartment complex.
His brother, a soldier on active duty, was killed in a car crash last year in Virginia, according to Stars and Stripes newspaper.
Soon after the shooting began Monday, heavily armed officers swarmed the school in a large industrial park near the Oakland airport. For a time, police believed the gunman could still be inside. But he wasn't.
Instead, officers said he apparently drove about three miles from campus before surrendering to officers inside a supermarket.
Police first received a 911 call at 10:33 a.m. reporting a woman on the ground bleeding. As more calls came in from the school, the first arriving officer found a victim suffering from a life-threatening gunshot wound, he said.
More officers then arrived and formed a perimeter around the school on the belief that the suspect was still inside, he said.
Jordan said there were about 35 people in or near the building when gunfire broke out. Of the seven fatalities, five died at the scene and another two at the hospital.
The three surviving shooting victims were all released from Highland Hospital by Monday night, according to hospital officials, who would not release details on the nature of the injuries treated.
Art Richards said he was driving by the university on his way to pick up a friend when he spotted a woman hiding in the bushes. He pulled over and, when he approached her, she said, "I'm shot" and showed him her arm.
"She had a piece of her arm hanging out," Richards said, noting that she was wounded near the elbow.
As police arrived, Richards said he heard 10 gunshots coming from inside the building. The female victim told him that she saw the gunman shoot one person point-blank in the chest and one in the head.
Tashi Wangchuk, whose wife witnessed the shooting, said his wife was in her vocational nursing class when she heard gunshots. She locked the door and turned off the lights, Wangchuk said he was told by his wife.
The gunman "banged on the door several times and started shooting outside and left," he said. Wangchuk said no one was hurt inside his wife's classroom, but that the gunman shot out the glass in the door. He said she did not know the man.
"She's a hero," he said of his wife.
Goh fled from the school in a Honda Accord that belonged to one of the victims, Jordan said. The suspect was detained at a Safeway supermarket about three miles from the university, about an hour after the shooting.
A security guard at the supermarket approached the man because he was acting suspiciously. The man told the guard that he needed to talk to police because he shot people, and the guard called authorities.
Goh also called his father soon after the shooting and told him what happened, the chief said. The father called authorities.
Police went to the Westlake Christian Terrace senior housing complex on Monday afternoon to speak with a relative of Goh, Nam Ko Young, who's believed to be the man's father, said Young's neighbor, Barbara Ferguson.
Authorities have not released the names of the fatalities.
School secretary Katleen Ping is believed to be among the first victims of the shooting, according to her family.
Ping's father, Liberty Ping, said she had been working at Oikos for less than a year and had come to the U.S. from the Philippines in 2007. He described her as the rock of the family who leaves behind a 4-year-old son.
"We're just focusing on the positives," Liberty Ping said. "She's with the Lord. She's in a better place right now."
Associated Press writers Paul Elias in Oakland, Calif., and Louise Chu, Garance Burke and Marcus Wohlsen in San Francisco contributed to this report.