A man who was seen arguing with his wife early Tuesday killed his four young children in their home with a hunting rifle before turning the gun on himself, officials said.
All the children apparently died from gunshots to the head, while their father, Trevor Branscum, 38, died of a self-inflicted wound, according to Mayor Jim Bonta. Police told the mayor that Branscum had to reload the rifle before each shot.
"It wasn't some outsider coming in," Bonta said. "It erupted from within."
Authorities identified the dead siblings as Aubrie Branscum, 12; Jacob, 10, and twins Taylor and Alyssa, 5.
The bloodshed -- the first reported slayings in the San Joaquin Valley town of Gustine in nearly four decades -- occurred a little more than an hour after the owner of Borrelli's Market called police about an argument Branscum and his wife, Amanda, had in his store just after midnight.
The disturbance started after Amanda Branscum came in to buy a few things and her husband followed her into the market, according to police. The merchant said that as the woman drove away, her husband dove out of a window of the van.
Police said as officers searched for the van, another call came in of shots fired at the Branscum home.
Officers saw Amanda Branscum lying in the road uninjured; the bodies of Trevor Branscum and the children were inside the house.
Amanda Branscum, who left the house with a female friend after the argument, told police she saw her husband's body when she walked to the front door upon her return, but did not enter the house.
The children appeared to be sleeping when they were shot, Gustine Police Sgt. Vince Inaudi said.
Steven Morris, 18, who lived across the street from the Branscums, said he saw the family lighting fireworks on their front lawn Monday night.
"They always seemed really happy," Morris said. "I never heard any arguments from the house."
Inaudi said evidence at the scene was consistent with a murder-suicide but that the department planned to conduct a full homicide investigation.
Trevor and Amanda Branscum were married on Valentine's Day in 2003, Inaudi said, and were the parents of all four children.
They had lived in Gustine for three years.
Grief counselors were in Gustine on Tuesday afternoon and available to all residents troubled by the slayings, Bonta said.
"It's kind of shocking in this area," said neighbor Francisco Torres, 41, whose daughter was friends with Aubrie. "You always hear about crime in other cities, but it's shocking because it's your own neighbors."