Police early Wednesday still were at a junkyard where four men were shot to death in what was called "a case of workplace violence."

"We have a lot of work to do here," Police Chief Danny Macagni said earlier Tuesday. "We have a very large crime scene."

The shootings at Black Road Auto outside were reported about 4 p.m. Tuesday. By the time police and medics arrived all four were dead, Macagni said. A suspect was taken into custody at the scene.

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

The semiautomatic handgun used in the shootings was found at the scene.

"This is a case of workplace violence," the chief said. Macagni called the shootings "very deliberate," and police said the suspect likely reloaded at least once during the attacks.

"There were probably a dozen people here when we arrived that had witnessed the shootings," Lt. Dan Ast told KCOY television. None of the bystanders was injured, police said.

The suspect was detained for questioning, but his name won't be released until he is arrested and booked, said Lt. Chris Vaughn.

Police aided by California Highway Patrol helicopters searched the area to see if there were more victims, but Macagni said that 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.