A Californian city is on high alert after multiple stabbings - including a homeless woman being knifed through her tent.
Residents of a Northern California university town in Davis, US, are on edge after three people were stabbed within a week - with two fatal.
And on Monday night, a homeless woman reported being knifed several times through her tent.
Davis Police Chief Darren Pytel said he could not say whether they are searching for one or multiple suspects.
He also said he could not recall any incident like these in his four decades on the Davis police force and neither could officers who went back longer.
"This is different and the attacks were particularly violent and brazen," Mr Pytel said at a Tuesday press conference, adding that in the most recent two attacks, the "suspect didn't seem to care there were several witnesses" who could identify him.
Davis is a small city known for its laid-back vibe, bicycle-friendly infrastructure and the University of California, Davis.
There are roughly 67,000 residents in the city in addition to more than 13,000 students who live on campus.
The city is about 70 miles northeast of San Francisco and 15 miles west of Sacramento, California.
Police issued a shelter-in-place order shortly after the stabbing of the woman was reported at 11:45 p.m. Monday.
It was lifted hours later after police said they had not caught the suspect, who is described as a male with long curly hair, a thin build and carrying a brown backpack.
The description was "substantially similar" to descriptions of the suspect from the second homicide, Mr Pytel said.
The Federal Bureau of Investigation is assisting the Davis Police Department, as are other law enforcement agencies.
The first death was reported Thursday before noon when officers found an unresponsive male in the city's downtown Central Park.
The victim, David Henry Breaux, 50, was well known in the area for more than a decade as the "Compassion Guy," the mayor and city council said in a statement.
Breaux often greeted people and asked for their views on compassion, according to the statement.
The second stabbing occurred Saturday around 9:15 p.m. when a resident heard a disturbance and went outside to find a young man at Sycamore Park with multiple stab wounds.
Authorities identified the victim as Karim Abou Najm, 20, a student at the university and a graduate of Davis High School.
In Monday's stabbing, the suspect was spotted by several people at a homeless encampment before stabbing the woman several times through her tent, the police chief said. The woman, whom police have not identified, is hospitalized and in critical condition.
Pytel said he believes all the attacks occurred at night and urged residents to be vigilant of their surroundings and to travel in groups.
He said the department is scouring through hundreds of tips and searching for DNA evidence.