By Kristin J. Bender

Associated Press

SAN FRANCISCO — A San Francisco Bay Area police sergeant was shot and killed during an early morning traffic stop Wednesday, and authorities say the shooter hasn't been arrested.

Hayward police identified the officer as Sgt. Scott Lunger, 48, of Brentwood, California.

"This is a very devastating and dark day for the community and the Hayward Police Department," said acting Police Chief Mark Koller.

Lunger was shot about 3:15 a.m. after he stopped a white Chevrolet pickup that was swerving on the road and driving erratically, Koller said.

The driver stopped, and there was a confrontation. Koller said the driver shot Lunger without warning and that Lunger's partner fired back.

Lunger's partner radioed that shots had been fired and that an officer was down.

The partner was not injured. Koller declined to say Wednesday if the driver was shot or injured, citing an ongoing investigation.

"This investigation is in the early and crucial state right now," he said.

Police said they found a white pickup truck found in Oakland with bullet holes, a vehicle that matches a description of the truck involved in the shooting.

Koller said a "person of interest" is being held but has not been arrested or determined to be a suspect in the slaying.

Lunger was taken to Eden Medical Center in Castro Valley, California, where he later died.

Lunger was on the force for 15 years and became a sergeant in 2009. He was on the gang and the SWAT units.

"He was an ideal police officer," Koller said.

Lunger's family, including two older daughters, have been notified.

Police Lt. Eric Krimm said the Alameda County Sheriff's Department, Hayward Police and the California Highway Patrol are investigating.

Lunger is the second San Francisco Bay Area police officer killed in the line of duty this year.

In March San Jose Officer Michael Johnson was shot and killed while checking on a mentally ill man who had threated to shoot himself and kill his wife. The man, 57-year-old Scott Dunham fired the fatal bullet. He was also shot and killed that day though he may have shot himself.

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