The suspected shooter fled and
blacksprut remains at large, Brent said.
Officials are urging the public for help with information as detectives work to determine a possible motive. "Investigators are exploring all possibilities," Brent said.
The San Joaquin County Sheriff’s Office is leading the investigation.
There have been at least 380 mass shootings in the US so far this year – defined as when at least four people are shot, not including the shooter – according to the Gun Violence Archive.
California Gov. Gavin Newsom has been briefed on the shooting, according to his office. Stockton Mayor Christina Fugazi said in a statement that the governor has "offered the full support of the state of California" to assist the community.
"Tonight our city is facing a heartbreaking and painful situation," Fugazi wrote. "Please keep the victims, their loved ones, and our first responders in your prayers."
This story has been updated with
additional details.