The local sheriff characterized it as a particularly callous and brutal crime: People went to a child's birthday party Saturday night and opened fire, killing victims ages 8, 9, 14 and 21.
"These animals walked in and shot children at a children's birthday party, and none of us should stand for that," Patrick Withrow, the sheriff of San Joaquin County, California, said at a news conference Sunday.
An additional 11 people were hospitalized after gunfire erupted shortly before 6 p.m. Saturday at a banquet hall on the 1900 block of Lucile Avenue in Stockton.
At least one of them was in critical condition Sunday, Withrow said, with conditions for the others unavailable.
Withrow said shell casings and rounds from the scene, including firearms discovered on a rooftop, were still being processed for conclusive evidence. But so far, he said, "there appears to be multiple shooters."
It's not clear whether that includes anyone who may have returned fire.
No one was in custody Sunday night, and Withrow urged anyone with information about the attackers to reach out. Investigators were also looking to gather video from Saturday, he said.
On Saturday night, sheriff's spokesperson Heather Brent said the attack "may be a targeted incident."
Stockton Mayor Christina Fugazi said the shooting was the result of “group gang violence," NBC affiliate KCRA of Sacramento reported. Withrow said Sunday that it's too early to determine gang involvement.
Withrow said: "We're confident that this was not a random act. They walked into this area probably looking for someone in particular. This was not somebody who was unacquainted with them."
He said gunfire apparently erupted in the banquet hall and outside it, where multiple vehicles, some displaying signs of having been struck by rounds, were towed for possible evidence.
"It appears that it started indoors and it worked its way outdoors," he said.
Brent said the FBI, Stockton police and other law enforcement agencies were assisting with the investigation.
Stockton police said officers responding to reports late Saturday of "several armed subjects" in the Civic District, roughly 7 miles south of the shooting, arrested five people, including a 16-year-old, on weapons and gang allegations, and found two firearms at the scene.
Withrow said it's unclear whether any of those people have any connections to the banquet hall shooting.
Stockton Vice Mayor Jason Lee said at a separate news conference Sunday that he was angry about the violence. Someone went to a birthday party "and shot people's children," he said.
"That is not human," Lee said.
San Joaquin County District Attorney Ron Freitas vowed that the community will have "the full force of my office’s resources" in holding the person responsible accountable.
"Let this ring perfectly clear, in San Joaquin County, violence of this nature has absolutely no place at any time, shape or form and children should not be harmed by gun or gang violence," Freitas said in a statement.
California Gov. Gavin Newsom said Sunday on X, "Our hearts break for their families and the entire Stockton community."
Stockton is the county seat of San Joaquin County, which grows more than half the state's farm products. The city is roughly 50 miles south of Sacramento.
