SALT LAKE CITY — A University of Utah student and track athlete who was shot and killed on campus by a former boyfriend had filed a police complaint against him after she learned he was a sex offender and broke off the relationship, authorities said Tuesday.

Investigators had been working to build a case after receiving the report from 21-year-old Lauren McCluskey, a senior from Pullman, Wash., university police chief Dale Brophy said. He declined to disclose further details on the report.

McCluskey was found shot in a car Monday night near on-campus student housing. Her attacker, 37-year-old Melvin Rowland, killed himself overnight at a church when police tracked him down after linking him to the killing through a description, clothing and evidence at the scene, authorities said.

The victim’s mother, Jill McCluskey, said her daughter had filed a harassment complaint after breaking up with Rowland.

Lauren McCluskey had dated Rowland for about a month then ended the relationship on Oct. 9 when she learned he had lied about his age, name and criminal history, Jill McCluskey said in a statement. It wasn’t clear how the two met.

Jill McCluskey said she had been talking on the phone with her daughter as she returned from a night class and heard her yell, “‘No, no, no!”’

“I thought she might have been in a car accident,” Jill McCluskey said. “That was the last I heard from her.”