Those killings Monday came just two days after another mass shooting in a Los Angeles suburb that left 11 dead.
The back-to-back massacres - one of California's bloodiest spates of mass gun violence in decades - have left residents reeling, and prompted Governor Gavin Newsom to tweet: "Tragedy upon tragedy."
Little connects the two attacks, except one detail: both suspected gunmen were of retirement age... a rarity in a nation where mass shootings have become numbingly frequent.
"Cases like this, we've never had one in this county of this many deaths, at one scene, or one time."
The suspect in Monday's shooting in Half Moon bay was identified as 67-year-old Chunli Zhao. A spokesperson on Monday said Zhao was cooperating in the probe, but declined to give any further details about the case, other than this:
"All the evidence right now points to a workplace violence incident."
Police said the suspect was employed at the Mountain Mushroom Farm. The victims were seven men and one women, all them either Hispanic or Asian.
Meanwhile mourners brought candles to a vigil in Monterey Park, where a gunman opened fire in a ballroom dancing club on Saturday.
Authorities said the suspect in that shooting, 72-year-old Huu Can Tran, was found dead of an apparent self-inflicted gunshot wound inside a van on Sunday morning.
"We served a search warrant at the suspect's residence in the city of Hemet.
The Los Angeles County Sheriff on Monday said they'd found ammunition and what appeared to be an effort to make firearm suppressors in Tran's home. But they had no motive for the attack.
"The question is, there's information out there that the suspect may have committed these crimes, and I'm paraphrasing, due to jealousy or some relationship issues. We're hearing those things, too, but have not confirmed any of that information. It's part of what our investigators are diligently looking into."
A database of 185 mass shootings between 1966 and 2022 maintained by the nonprofit Violence Project includes just one carried out by someone 70 or older: a retired miner who killed five people in Kentucky in 1981.
