The knife-wielding attacker, who killed a retired Cal State Fullerton administrator, left a backpack at the scene with evidence that he might have also been planning a kidnapping, authorities said Tuesday.

Fullerton police were still searching for the killer of 57-year-old Steven Shek Keung Chan, who was fatally stabbed in a parking lot of the California State University campus at about 8:27 a.m. on Monday.

Police also on Tuesday released security video showing a man, wearing all black, running away from the parking lot where Chan was killed.

Investigators found a backpack they believe belonged to the killer under Chan's car that contained "an incendiary device, along with numerous items that were consistent with a kidnapping attempt or plot, including zip ties, wigs and other disguise materials as well as a knife (that was not used in the homicide)," Fullerton police said in a statement Tuesday.

The suspect, in his mid-20s, ran from the crime scene and escaped in a black four-door sedan that investigators believe is a newer model BMW X6, police said.

Chan was a budget and finance director at Cal State Fullerton from from 2009 to 2017 who returned to school earlier this year as a consultant, university president Fram Virjee said in a statement.