Tehama County sheriff's deputies arrested 32-year-old John Noonkester on Thursday. He remains jailed.
A woman called 911 shortly after 4 p.m. local time and said she had been battered before the call disconnected, Assistant Sheriff Phil Johnston said.
Moments later, a shooting was reported in the gated Lake California community, 130 miles north of Sacramento, according to AP.
Deputies found a 29-year-old woman and a 53-year-old man dead outside the store.
Johnson said a bullet hit a man inside, who was treated at a hospital.
Witness David Lewis told the Redding Record Searchlight the gunman apparently argued with his ex-wife and her father.
According to Johnson, the victims were related and knew the gunman.