A Korean-American former nursing student pleaded not guilty Monday to killing seven people in a shooting rampage at a religious college in California.

One Goh, 43 -- who has refused to eat for several weeks -- is charged with seven counts of murder and three counts of attempted murder for the April 2 shooting at Oikos University, a small Christian schoolin Oakland.

Law enforcement officials say Goh, a US citizen originally from South Korea, was angry about a denied tuition refund when he arrived at his former school with a .45-caliber gun and four loaded magazines of ammunition.

Apparently unsuccessful in locating the administrator he sought, Goh opened fire and "essentially executed" seven people and wounded three others, prosecutors said.

After fleeing the scene in a victim's car, Goh admitted to a grocery store security guard that he had killed several people, according to a police statement included in court filings.

Goh -- who officials say left the school voluntarily last November -- also admitted "kidnapping a woman and forcing her from her office into a classroom at gunpoint," the statement says.

Those killed were: Doris Chibuko, 40; Judith Ona Seymour, 53; Grace EunHea Kim, 23; Lydia Sim, 21; Tshering Rinzing Bhutia; Sonam Choedon, 33; and Katleen Ping, 24. All were students except Ping, who was an administrative worker.

Prosecutors will decide whether to seek the death penalty after a judge holds a preliminary hearing to determine whether there is enough evidence for the case to go to trial -- a routine step in US courts.

Alameda County Sheriff's Office spokesman Sergeant J.D. Nelson said Goh has lost about 20 pounds as a result of refusing to eat for several weeks.

The defendant is drinking liquids and has not given a reason for refusing food. Nelson said he would not characterize the act as a suicide attempt or a hunger strike.

"He has the right not to eat," Nelson said. "We can't force him to eat."

The shooting has been particularly traumatic for the local Korean American community and has revived painful memories of the 2007 Virginia Tech University shooting, carried out by Korean American Seung-Hui Cho, who killed 32 people.

"Many people didn't want the reminder of that tragedy," said Pastor Hyok-In Kwan of the Berkeley Korean United Methodist Church. "They don't want people to think of Koreans negatively."

Joyce Park of the Korean Consulate General in San Francisco said the community has also turned inward, wondering how no one noticed Goh was so troubled.

"They feel really sad and sorry," she said. "They're asking, 'How come nobody knew about his problem?' -- Why couldn't we prevent this?'"

CBS 5 has reported that Goh expressed remorse for the killings in a jailhouse interview.

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."

Goh will be back in court for a hearing on June 25.