As authorities continue to investigate Monday’s mass shooting in Half Moon Bay that left seven people dead and one injured, officials on Tuesday said the massacre appears to be a case of workplace violence.

The mass killing took place at two mushroom growing locations, one at about 2:20 p.m. on San Mateo Road (Highway 92) and the other shortly thereafter along Cabrillo Highway South (Highway 1). Multiple victims were found at both scenes.

The suspect, 66-year-old Chunli Zhao, worked at the first shooting location, Mountain Mushroom Farm, and he either worked with or used to work with the victims at the shooting scenes, the sheriff’s office said. Investigators believe he acted alone.

“All of the evidence we have points to this being the instance of workplace violence,” San Mateo County Sheriff Christina Corpus said Tuesday.

Zhao was taken into custody without incident at about 4:40 p.m. Monday in the parking lot of a San Mateo County sheriff’s substation in Half Moon Bay after a deputy spotted his vehicle.

A semi-automatic handgun was found in Zhao’s vehicle. The sheriff’s office said the firearm was legally purchased and owned.

Zhao was booked into the Maguire Correctional Facility in Redwood City on seven counts of first-degree murder and one count of first-degree attempted murder, the sheriff’s office said. Each count includes an enhancement for using a firearm. {snip}

“We’re not going to be giving out a lot of precise detail on what was said,” San Mateo County District Attorney Steve Wagstaffe said. {snip}

Authorities did not immediately release information pertaining to Zhao’s criminal history.

“There were no specific indicators that would have led us to believe that he was capable of something like this,” sheriff’s office spokesperson Eamonn Allen said. “He was not known to us or to have any sort of, again, indicators that may have led us to believe that this was something he might have done.”

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All of the victims are Asian or Hispanic, according to the sheriff’s office. Their identifies will be released publicly following notification of next of kin.

“As some of these victims were members of our migrant community, this represents a unique challenge when it comes to notifications and identifications,” Corpus said.

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The shootings in Half Moon Bay marked California’s second mass shooting in three days. On Saturday, a gunman opened fire at a dance studio in the Southern California city of Monterey Park, leaving 11 dead and nine injured.

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