Read more about this story from CNN affiliate KGO.
(CNN) -- One Goh, the 43-year-old Korean-American man suspected in the execution-style shooting deaths at a small Christian college in California, seemed a doting son visiting his parents in senior housing. But at the same time, he was capable of displaying unbridled anger at the school, according to police and others who had contact with him.
The portrait of Goh emerging one day after six women and one man were shot to death at Oikos University in Oakland is of someone who felt he was "teased" and "picked on" at the college, which eventually expelled him, possibly for poor behavior, police said.
Goh was self-conscious of his inability to speak English like a native and felt that students and others at the school made fun of him, police said.
Oakland Police Chief Howard Jordan said it wasn't immediately clear why Goh had been expelled from the college but, "We've been told that some of the possibilities are that he was expelled for his behavioral problems, anger management, but nothing specific."
While Goh appeared close to his family, he struggled personally with significant debt, including a tax lien by the Internal Revenue Service, according to court records. His brother, a soldier, reportedly was killed last year in the line of duty. CNN affiliate KGO said the brother, a staff sergeant in the Army, died in a car accident while training with the Special Forces.
After the shooting, which just lasted minutes, the gunman drove off in a victim's car, and when the suspect surrendered to police at a grocery story in the Oakland suburb of Alameda, the gunman showed no remorse and told police he was angry about his expulsion from the college, police said.
No charges have been filed yet in the mass killing as police continue their investigation, authorities said. Goh was being held Tuesday in Alameda County's Santa Rita Jail pending an initial appearance in court this week.
The early, broad impressions of Goh have drawn the attention of civic and church leaders in the city's Korean-American community, who were scheduled to attend a memorial service in Oakland Tuesday evening. Community leaders will work together to help those living in the area and those affected directly cope with the tragedy, said June Lee, executive director of Korean Community of the East Bay, based in Oakland.
Oikos University, located in a one-story structure that resembles a converted office building, caters to the Korean-American Christian community but also has students from diverse backgrounds. It offers degrees in theology, music, nursing and Asian medicine, according to its website.
"First of all, we would not want to localize this story too much," Lee told CNN. "We think that Koreans or Asians are mainstreamed. We're not so much different from others. It is a tragedy and we recognize that. We're looking for a way to help the families and the community that are impacted by this incident."
Community and faith leaders have yet to determine what issues need to be raised in the aftermath of the mass shooting, she said.
"We need to identify the issues first. All the community leaders are willing to convene and to have a collective strategy in the community," Lee said.
Meanwhile, Police Chief Jordan said that Goh, after he surrendered, didn't appear "to be remorseful at all."
CNN's Ashley Hayes and Catherine Shoichet contributed to this report.