A Stanislaus County (CA) sheriff's deputy was shot at point blank range and killed in the line of duty Sunday, police said. Sheriff Adam Christianson called the killing “an execution.”

Christianson said that Dep. Dennis Wallace, a 20-year veteran of the force, was shot twice around 8:30 a.m. while investigating a suspicious person and vehicle near a fishing access in Hughson, a city roughly 10 miles outside 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."

The suspect, who has been identified as 37-year-old David Machado, fled the scene and carjacked an escape vehicle in the nearby city of Ceres, Christianson said. He was apprehended later Sunday afternoon.