A former University of California, Irvine student threw his mother off a multi-story campus building before plunging to his own death in what investigators believe to be a murder-suicide.

The incident happened just before 4 p.m. Tuesday at the university’s Social Science Plaza B, Irvine police said.

The victim was identified as 77-year-old Thao Thai Nguyen of Irvine. The suspect was identified as her son, 36-year-old Andrew Doan, also of Irvine.

Investigators said Doan picked up Nguyen and tossed her off the landing of the building. Doan then jumped to his death from the same landing.

3 DEAD, 1 INJURED IN MURDER-SUICIDE SHOOTING IN PORTLAND

UC Irvine campus

Detectives were investigating a motive for the suspected murder-suicide at UC Irvine on Tuesday. (Allen J. Schaben / Los Angeles Times via Getty Images)

Doan was a biological sciences major at UC Irvine from September 2017 to June 2019, but he didn't graduate, UCI spokesman Tom Vasich told the Los Angeles Times.

Police had contacted him several times in the past. The last time was in 2019 and involved "mental health concerns," the statement said.

Investigators were trying to determine a motive for the murder-suicide, police said.

UC Irvine campus

UC Irvine Chancellor Howard Gillman said the university was "fully cooperating" with police as they continue to investigate the deaths.  (Allen J. Schaben / Los Angeles Times via Getty Images)

Chancellor Howard Gillman said in a written statement that the university was "fully cooperating" with police as they continue to investigate the deaths. 

CLICK HERE TO GET THE FOX NEWS APP

"At such a time, our primary thoughts are with the victims and their families," Gillman said. "But there are also members of the UCI community who have been contacted to assist with the investigation and to share their knowledge of what may have happened."

The Associated Press contributed to this report.