The former student suspected of killing seven people and wounding three at a tiny religious college in Oakland felt mistreated by classmates, was deeply in debt and had two deaths in his immediate family last year, the Oakland Tribune reports.

View Photo Gallery: Police say a suspect has been detained after attack at Oikos University, a Christian school in Oakland.

Monday’s shooting was the Bay Area's worst mass murder in almost 20 years. The victims include six women and a man, and range in age from their 20s to 40s. The shooting suspect, One Goh, 43, told police that he shot all seven people execution-style, CNN reports. In one classroom, he said, he lined up students against a wall and shot them one by one.

Goh was apprehended at a supermarket Monday about an hour after the shooting. He was arrested Tuesday morning on seven counts of murder, three counts of attempted murder, carjacking and kidnapping, authorities told the Oakland Tribune. The kidnapping count refers to a receptionist taken hostage during the shooting.

During questioning, Goh told investigators he left the school voluntarily in November because school administrators and students had started treating him differently than other people. He told investigators people were “not treating him respectfully.”

Goh said one female administrator at Oikos University was the focus of his fury. Police told the Oakland Tribune said she is not among the injured.

Goh was born in Korea and is a naturalized U.S. citizen, according to the Oakland Tribune. His last known address is at his father's apartment in Oakland.

The suspect had just faced two deaths in the family. His brother, an army sergeant, died in a traffic accident in March of last year, and his mother died shortly after. Goh also has a brother who lives in Virginia.

According to Oakland police, Goh was deeply in debt, with federal tax liens in 2006 and 2009 adding up to more than $23,000, ABC News reports. He was also evicted from an apartment complex in his former home state of Virginia, according to ABC.

Oakland police said Goh had no known previous criminal record.

Goh was a former nursing student at Oikos University, an eight-year-old evangelical Christian college that attracted mostly Korean students.

Oikos University required its students to attend church services and follow strict rules, Inside Bay Area reports. On a list of institutional objectives on its Web site, the school’s number one objective is for students to “demonstrate a comprehensive knowledge of the Bible and an understanding of Christian doctrine.”

The university is so tiny it shares space with several businesses. It has about four dozen faculty members, many of them part-time.

Officials said after the shooting that the school was closed indefinitely.