A Korean-American arrested over a massacre at a religious college in California was charged with seven counts of murder on Wednesday, prosecutors said, adding that he had admitted the crimes.
One Goh, 43, who surrendered a short time after the killings Monday in Oakland, near San Francisco, was also charged with three counts of attempted murder, said the Alameda County district attorney's office.
The suspect, a former student at the college, confessed to the killings using a .45 caliber handgun and four fully loaded magazines of ammunition, according to a brief police statement appended to his charge sheet.
"The enormity and devastation of these crimes is unprecedented in Alameda County," District Attorney Nancy E. O'Malley said in a statement. "My office will work tirelessly to ensure that this defendant is brought to justice."
Calling the killings "brutal," she pledged to help "surviving victims and the families of those victims who were senselessly murdered to help them navigate this unimaginable tragedy and the legal process as it unfolds."
The suspect -- identified by South Korea's Yonhap news agency as Ko Won-Il -- allegedly launched his rampage at the Oikos University after being expelled, while also being upset at having been picked on by fellow students, police say.
"He was distraught because he was picked on ... He planned (the attack) several weeks in advance," Oakland police chief Howard Jordan said Tuesday, adding "he has not shown any remorse" about the killings.
Some 35 people were in or near the building at the time. Of those, 10 were hit and five were pronounced dead at the scene. Two others died later in hospital. Survivors were found hiding in locked and darkened rooms.
The charge sheet named the victims of the massacre, and cited also "special circumstances" of the killings, including one of carjacking -- Goh allegedly commandeered a car to escape after killing its owner.
It also cited a detective's "probable cause statement" about the killings, based on an interview with Goh after his arrest.
"During the interview, the suspect admitted to going to (the college) in Oakland with a .45 caliber handgun and four fully loaded magazines of ammunition.
"He admitted to kidnapping a woman and forcing her from her office into a classroom at gunpoint.
And it said: "He admitted to shooting and killing several people inside the classroom, before taking one of the victim's car keys and fleeing the scene in the victim's car."
Oakland Mayor Jean Quan said the city was trying to recruit more Korean-speaking grief counselors, saying the shooting "will leave the community asking questions for a long time."
The Oakland Tribune reported that the suspect's brother, US Army Sergeant Su Wan Ko, died in a traffic accident in Virginia in March 2011 while on special assignment from a research institute in Germany.
The college where the shootings took place offers degrees in nursing, biblical studies and Christian ministry. Its website says "students are given the opportunity to obtain a Christian education that is based on solid Christian doctrine and ideology."