A California deputy was shot and killed in the line of duty Sunday morning in what authorities are calling an execution.

Stanislaus County Deputy Dennis Wallace was shot and killed while on duty this morning at Fox Grove Park in Hughson.

At a press conference, Sheriff Adam Christianson said Wallace entered the fishing access area of Fox Grove Park after reporting a suspicious vehicle. Once he learned the vehicle was stolen, Wallace called for back-up. Christianson said within seconds, he was executed. When deputies arrived, they found Wallace with two gunshot wounds to the head.

The suspect was identified as David Machado. He was last seen wearing a blue shirt and a blue and gray baseball cap. Machado fled the scene, then carjacked a vehicle in Keyes. Christianson believes he is driving a 2009 white Kia Rio, with CA Plate 6JIS245.

RELATED: Mugshot gallery

An active man-hunt is underway for Machado. Law enforcement Machado is considered armed and dangerous. Machado is a known criminal with preexisting felony warrants out for his arrest.

They warn that anyone who sees him should not approach and should instead call 911.

“No peace officer should be killed in the line of duty,” Christianson said.

Wallace, 53, was a 20 year veteran of the sheriff's department. Christianson noted he was well known in the organization, particularly for his work with the D.A.R.E program. He leaves behind a wife and family.

Law enforcement blocked off the scene from pedestrians and closed fishing access and the investigation continues.