A co-worker has been arrested in the slaying of a retired California college administrator who was stabbed to death on campus, police said.
Chuyen Vo, 51, is accused of killing Steven Shek Keung Chan, 57, who was found in a car in a campus parking lot with "numerous" stab wounds on Monday morning, according to authorities.
A "crude incendiary device" was left in a backpack underneath Chan's car, as well as items that could be used in a kidnapping, like zip-ties and wigs, police said.
Authorities believe Vo -- who was arrested at his home Wednesday night for murder -- acted alone, Fullerton Police Chief Robert Dunn said at a news conference on Thursday.
On Friday, Orange County prosecutors filed charges against Vo. He is charged with one count of murder, an enhancement for the use of a knife, and a special circumstance allegation of lying in wait.
He faces a minimum of life in prison without parole if he's convicted.
Chan was the director of Budget and Finance and Student Services for University Extended Education from 2009 until he retired in 2017, CSU Fullerton President Framroze Virjee said. Chan returned to campus as a special consultant in 2019.
While the suspect and victim were co-workers at CSU Fullerton, authorities are still working with prosecutors to determine a motive, the chief said.
Police did not say if the suspect worked with Chan before his retirement or when he returned to campus this year.
Virjee said earlier this week that Chan "was beloved for his commitment to and passion for both Cal State Fullerton and our Titan Family."
ABC News' Alex Stone contributed to this report.