A 21-year-old man who had been a student at the University of California, Davis, until last week was arrested for allegedly stabbing three people, including two fatally, and sending fear through the quiet college community, city police said.

Davis Police Chief Darren Pytel said Thursday that Carlos Dominguez was taken into custody Wednesday after 15 people called in reports of a person who matched the description of the suspect near a downtown park where he is accused of stabbing his second victim to death.

Pytel did not disclose a motive for the stabbings and said they do not yet know how or if Dominguez knew his victims.

“He was out wandering a neighborhood where the second homicide had occurred. He had a large knife in a backpack, wearing the same clothes from the third stabbing,” said Pytel. “That’s highly unusual and unique.”

UC Davis officials said in a statement that Dominguez was a third-year student majoring in biological sciences until April 25, “when he was separated for academic reasons.”

It wasn’t immediately clear if Dominguez had an attorney who could speak on his behalf.

NBC affiliate KCRA-TV in Sacramento, California, reported it captured aerial footage of police Wednesday afternoon speaking with a person near a downtown park where the second victim, a 20-year-old student at the University of California, Davis, was killed.

Officers were then seen placing the person in the back of a patrol car.

Davis is a small city about 70 miles (112 kilometers) northeast of San Francisco and 15 miles (24 kilometers) west of Sacramento. There are roughly 67,000 residents in the city in addition to more than 13,000 students who live on the UC Davis campus.

Davis police did not return phone calls and emails seeking more information.

The first death was reported Thursday when officers found David Henry Breaux, 50, in downtown’s Central Park, hunched over a bench where he often sat or slept.

The second victim, Karim Abou Najm, was found Saturday night at Sycamore Park with multiple stab wounds.

A homeless woman who is in her 60s was the victim of Monday’s stabbing.