A Stanislaus County Sheriff's deputy was shot twice in the head and killed Sunday while responding to a call about a suspicious car and person, authorities said. The suspect in the killing has been arrested.

Stanislaus County Sheriff Adam Christianson said Deputy Dennis Wallace, a 20-year- veteran, was shot at point-blank range as he checked on a report of a suspicious car and person near a fishing access spot outside the city of Hughson, about 10 miles southeast of Modesto.

"He was executed," Christianson said. "We believe that Dep. Wallace was killed outside of the car, and we know for a fact that the gun used in this crime was in direct contact with his head when the trigger was pulled twice."

Dispatch told Wallace the car was stolen, which prompted the deputy to request backup. A second deputy arrived and found him wounded. He was transported to a hospital where he died, the department said.

The suspect, who has been identified as 37-year-old David Machado, abandoned the stolen van and carjacked an escape vehicle in the nearby city of Keyes, it said.

Machado was arrested later Sunday in Tulare County, the department said, adding it wouldn't release details on his arrest at this time.