In an alert, the California Highway Patrol said the suspect, whose name was not known, is considered to be armed and dangerous.
Newman Police Officer Ronil Singh, 33, had called in the traffic stop early on Dec. 26 and a few minutes later reported shots fired over his radio, the Stanislaus County Sheriff’s Department said in a statement.
Multiple agencies responded and found Singh with gunshot wounds. They rushed the husband and father of an infant boy to a hospital where he was pronounced dead.
Ground and air units were searching for the suspect based on surveillance photos taken at a convenience store shortly before the attack.
The suspect was believed to be driving a gray Dodge Ram pickup truck when the shooting occurred in Newman, about 100 miles southeast of San Francisco.
“We have sent out information to law enforcement up and down the state, as well as outside California,” said Sgt. Tom Letras said, a sheriff’s spokesman.
In the photos, the heavyset suspect with short dark hair is wearing a thick chain necklace. jeans, a dark hoodie and dark-colored T-shirt.
Singh was a native of Fiji and had worked since July 2011 for the police department in Newman, a town of about 10,000 people. Earlier in his career, Singh worked as a deputy with the Merced County Sheriff’s Department.
On his Facebook page, Singh posted pictures on Christmas Eve from a deep-sea fishing trip that produced a big haul of crabs and fish. The profile picture shows him smiling as he stands at a patrol car with a dog — the same photograph of the officer released by the sheriff’s department.
Singh is survived by his wife, Anamika, and a 5-month-old son, authorities said.
Outgoing California Gov. Jerry Brown offered condolences to Singh’s family and said flags at the Capitol would fly at half-staff in his honor.
“Our hearts are with the entire community of Newman and law enforcement officers across the state who risk their lives every day to protect and serve the people of California,” Brown said.