(CBS/AP) OAKLAND, Calif. - The suspect in the Oikos University shooting reportedly bragged about being capable of violence and felt too old to be attending school, says an Oikos nursing instructor who knew him.
Since his arrest, details of 43-year-old One L. Goh's life have emerged that suggest a troubled man who has been struggling to deal with personal and family difficulties over the past decade.
"I don't know if you could call it mentally unstable, but sometimes he would brag that he was capable of hurting people," said Oikos instructor Romie John Delariman.
Delariman said Goh was one of his most eager students, but he felt disrespected by his younger classmates.
"He said he was too old to go school with all the young people, and he said all his classmates were mean to him," Delariman said.
Police have released little background information about Goh, other than to say he had become a U.S. citizen.
Goh, a nursing student originally from South Korean is accused of fatally shooting seven people Monday. He is being held without bail.
The San Jose Mercury News reports The Alameda County District Attorney's office is expected to file murder charges against him today.
District Attorney Nancy O'Malley said her office will file, at the very least, seven counts of murder and three counts of premeditated attempted murder against the South Korean national. O'Malley said her office will also allege a special circumstance against Goh for killing multiple people.
If he is convicted, Goh will face at least life in prison without the possibility of parole, and at the most the death penalty, O'Malley said.
Six students and a receptionist were killed and three others were wounded when Goh allegedly went on a shooting rampage Monday morning at Oikos University, an Oakland school founded to help Korean immigrants adjust to life in America and launch new careers.
Several hundred friends, family and community members gathered for a multicultural prayer vigil Tuesday night to mourn the victims.
"Only God knows the meaning of the suffering we endure," Dr. Woo Nam Soo, the university's vice president, said in Korean during the church service. "In this unbearable tragedy and suffering, only God can create something good out of it."
Shortly after the deadly shooting spree, police arrested Goh at a supermarket a few miles from campus.