Updated

Four men were shot to death in a junk yard Tuesday northwest of Los Angeles in what police said was "a case of workplace violence," and a suspect was taken into custody.

The shooting at Black Road Auto was reported about 4 p.m., and all four victims were dead by the time police and medics arrived, Police Chief Danny Macagni told the Santa Maria Times.

The victims, whose names were not immediately released, were shot at close range, Macagni said. One victim was found outside the junk yard, and three were found inside.

The gun used in the shooting was found at the scene.

"This is a case of workplace violence," the chief said. "We have a lot of work to do here. We have a very large crime scene."

Police aided by California Highway Patrol helicopters searched the area to see whether there were more victims. Macagni said police believed there was "a sole suspect that entered the premises and fired the shots."

Santa Maria is a city of 92,000 in northwestern Santa Barbara County.