LOS ANGELES — A student stabbed a psychology professor to death on the University of Southern California campus in Los Angeles on Friday in what was a personal dispute, authorities said.

Los Angeles Police Officer Meghan Aguilar said the professor was killed inside the Seeley G. Mudd building in the heart of campus. She said a male student was arrested without incident immediately after police arrived at the scene of the attack but his name was not released. Aguilar could not say who called police but said it wasn’t the professor or the student.

Aguilar said the student was set to be interviewed Friday night and that his name would be released after he was booked.

USC President C.L. Max Nikias identified the professor killed as Bosco Tjan in a letter addressed to the USC community.

Tjan joined USC in 2001, taught in the Dornsife College of Letters, Arts and Sciences, and served as co-director of the Dornsife Cognitive Neuroimaging Center, Nikias said.

“As the Trojan family mourns Professor Tjan’s untimely passing, we will keep his family in our thoughts,” Nikias said.

The USC Department of Public Safety said investigators believe the attack was not random and “was the result of a personal dispute.”

Chris Purington, project manager at Tjan’s lab, said he never heard of anyone having a problem with Tjan — a married father of one son listed in public records as 50 years old — and had no idea who would have wanted him dead.

“He was somebody who really cared about people. I know he cared about me,” Purington said through tears. “He mentored people and he looked out for them. He spent a lot of time thinking about what it means to be a mentor and guide people.”

USC has 44,000 students enrolled, including more than 10,000 international students.