7 people have been killed in 2 related shootings in Half Moon Bay, California

Updated 8:42 p.m.

By James Doubek, NPR

A man killed seven people at two landscaping nurseries in Half Moon Bay in San Mateo County, south of San Francisco, on Monday, law enforcement said.

The shooter was believed to be a worker at either one or both locations and the victims were also believed to be workers, San Mateo County Sheriff Christina Corpus said.

An eighth person was at Stanford Medical Center in critical condition, she said.

The suspect was identified as Chunli Zhao, a 67-year-old Half Moon Bay resident, the sheriff's office said. He is in custody and cooperating.

The two locations are about a mile away from each other, the sheriff said. Law enforcement does not have a motive for the shooting.

Sheriff's deputies arrived at the first location around 2:22 p.m. local time and found four victims dead of gunshot wounds, with a fifth victim also wounded. Three more victims were found at the second location soon thereafter.

Zhao was found in his vehicle in the parking lot of the Sheriff's Office Half Moon Bay Police Substation at 4:40 p.m. A semiautomatic handgun was found in his vehicle, authorities said. Zhao acted alone and there is no outstanding threat to the public, the sheriff's office said.

"This is a horrific event, one that we would never imagine would occur in San Mateo County," said San Mateo County Board of Supervisors President David Pine. "Gun violence in this country is at completely unacceptable levels and it's really hit home tonight."

The shooting comes less than 48 hours after a gunman killed 11 and wounded nine at a Chinese-owned ballroom dance studio in Monterey Park, a majority Asian American suburb of Los Angeles. The suspect, a 72-year-old Asian man, died by suicide. Authorities do not have a motive for that shooting.