COLUMBIA, S.C. (AP) — University of South Carolina professor Raja Fayad had a secret he kept from most of his family, colleagues and even the police until his death.

He was a victim of domestic abuse.

The abuse appeared to be mental and emotional until Feb. 5, when Sunghee Kwon pulled out a 9 mm pistol she bought for $90 at a pawn shop and killed them both after a 10-minute closed door meeting in his office.

The case report from the State Law Enforcement Division obtained and reviewed by The Associated Press shows a man who tried to keep his marriage and its failure a secret.

Fayad called university police three weeks before he was killed because Kwon refused to leave his classroom. He never told the officer that they had once been married. Police found that out after they left and ran them both through a public records database and determined their driver's licenses had the same address.

For years, South Carolina has had one of the highest rates of men killing women in the United States. There is a troubling sub-trend behind that number. About one in five people killed by domestic violence in the state has been a man, according to statistics gathered by the South Carolina Attorney General's Office.

It's an overlooked problem, made worse by a society that sees men seeking help as weak and men who fear losing their jobs or status if the world knows they are being abused by a spouse or partner, said Katie Ray-Jones, president of the National Domestic Violence Hotline.

"Most men think 'I can handle it' and 'I don't need help' because they are so ashamed about what is happening behind closed doors," Ray-Jones said. "They worry their manhood will be judged."

The report also makes clear that Fayad's situation was made worse by his culture. Fayad's brother told state agents he never told his mother or other family back in Lebanon that he married a Korean woman because he was expected to take a Lebanese bride.

The investigation into Fayad's death and his ex-wife's suicide starts in February 2009, when they were married in Chicago. The marriage ended less than five years later, and divorce records show an amicable separation. The couple bought a house in Lexington shortly after their marriage, and they both continued to live there for 14 months after their divorce.

Two months before the killings, Kwon had pushed to get into her husband's anatomy and physiology program. However, the head of the department said he did not back the idea, even if the couple was divorced. That appeared to put a great strain on the relationship. Fayad moved out.

Then Kwon began sending emails to a woman in Lebanon, accusing her of having an affair with Fayad.

"I am begging you, please return my Raja to me," Kwon wrote.

In December 2014, she bought plane tickets to follow Fayad to Lebanon. She emailed her itinerary to him, but he told her not to come.

"Do not make my mother have a heart attack," Fayad wrote back. "Don't ruin me any more. Please cancel the ticket."

Kwon canceled the flight, then sent her ex-husband a threatening email.

"You ruined my life," she wrote. "I will get you."

Over the next two months, Kwon repeatedly came to Fayad's office. On Feb. 5, she entered with a gun she bought five days before. The graduate student outside heard nothing for the 10 minutes Kwon was inside, then told investigators he heard several loud bangs, smelled gunpowder and saw blood coming from under the office door.

The medical examiner said Kwon shot Fayad in the head, chest and hand. Kwon then shot herself.