Students at the University of California, Davis, are on edge after a third unsolved stabbing in a week.

Officials lifted a “shelter-in-place” order Tuesday morning after a manhunt turned up empty as they pursued a suspect in another knife attack late Monday.

Monday’s stabbing is the third such incident. The most recent attack left a woman in critical condition, and follows the stabbing deaths of 50-year-old David Breaux and UC Davis senior Karim Abou.

The university’s chancellor, Gary S. May, announced yesterday that all classes that end after 6PM will now be held virtually, and he encouraged clubs and student activities that meet at night to also move to a virtual format for now.

Davis Police Chief Darren Pytel called the attacks “particularly violent and brazen.”

Pytel pointed to similarities between the three attacks. In the first two, victims were stabbed in city parks. In the second two attacks, the suspect or suspects interacted with witnesses. Pytel calls it bold behavior that poses “significant concern.”

Police have described the suspect in the first stabbing as a man with curly hair, a thin build and light complexion between 5-foot-6 and 5-foot-9 inches tall.

And the second and third stabbing suspect is “substantially similar,” according to police who described him as a “light-skinned male, possibly Hispanic between 19 and 23 years old and between 5-foot-7 inches and 5-foot-8 inches tall” with long curly hair.

Although they are still combing through tips and desperately searching for a concrete lead, police say that they are looking for DNA and will be providing a “very visible presence” in the area.