San Mateo Sheriff Christina Corpus said during a news conference Monday night that deputies were alerted to the shooting in unincorporated San Mateo County at 2:22 p.m. PT (5:22 p.m. ET).
Upon arrival, deputies found four people dead from gunshot wounds. A fifth victim was taken to Stanford Medical Center in critical condition. Three additional victims were later found at a separate shooting location, the corps said.
At 4:40 p.m. PT (7:40 p.m. ET), the corps says the suspected gunman — a 67-year-old man from Half Moon Bay — was taken into custody without incident. A handgun was found in his vehicle at the time, the corps said.
Corpus said he acted alone and his motive is unknown.