Updated at 12 p.m. ET: One Goh, the former Oikos University student accused of killing seven people at the college's campus in Oakland, Calif., told authorities he was upset with being expelled and had sought out a female college official who was not present, the city's police chief said Tuesday.
Goh "then went through the entire building systematically and randomly shooting victims," Oakland Police Chief Howard Jordan said at a news conference.
"We do know that he was upset at administrators at the school. We do know that he was upset with several students here because of the way he was treated when he was enrolled here two months ago," Jordan said.
He said Goh, 43, had been teased. The South Korean national had been expelled, possibly for behavioral problems, according to Jordan.
"They disrespected him, laughed at him. 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 the female administrator and began shooting when he learned she wasn't there, Jordan said. The victims, who range in age from 21 to 40, were from various countries, including Nigeria, Nepal and the Philippines.
Other reports indicated that Goh, who reportedly had been a nursing student, recently lost two family members and had debts.
In Monday's rampage -- the deadliest U.S. campus shooting since the 2007 Virginia Tech killings -- one witness said Goh told students: "Get in line and I'm going to kill you all."
Jordan said Goh first took a receptionist hostage and then went looking for a particular female administrator. He then took the receptionist into a classroom and, on realizing the administrator was not there, he shot the receptionist and lined students up against a wall.
Goh surrendered Monday afternoon at a grocery store several miles away from the scene.
Gunman kills 7 at small California university
Three others were injured but suffered non-life-threatening injuries, police told NBC Bay Area.
The station said at least one of the injured, a 19-year-old woman, was released from the hospital late Monday after suffering a gun shot wound to her arm.
The San Francisco Chronicle said Goh's brother, U.S. Army Sgt. Su Wan Ko, died in March 2011 in a car crash in Virginia while on special forces training.
It also reported that his mother, Oak Chul Kim, died a year ago in Seoul, where she moved after leaving Oakland, according to her former neighbors in Oakland.
Rent owed
The Chronicle said Goh used to live in Virginia, where records show a string of judgments against him, including an eviction from apartments in Hayes where he owed $1,300 back rent at the time he left.
Records show federal tax demands were issued in 2006 and 2009 for a total of $23,000, although the newspaper said he had managed to repay some of the money.
NBCSanDiego reported that Goh's parents lived in two different apartments in Chula Vista between 1998 and 2000, though exact details on the street locations of those homes remain unknown.
Paul Singh, whose 19-year-old sister Devinder Kaur was shot in the arm during Monday's rampage, told Reuters that according to his sister, Goh was a former student who showed up to class for the first time in four months.
"'Get in line and I'm going to kill you all,' is what he said this morning, my sister told me. They thought he was joking at first,'" Singh said.
Tashi Wangchuk, whose wife attended the school and witnessed the shooting, said he was told by police that the gunman first shot a woman at the front desk, then continued shooting randomly in classrooms.
Wangchuk said his wife was in her vocational nursing class when she heard gunshots. She locked the door and turned off the lights.
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.
The Associated Press contributed to this report.
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