An off-duty Washington State Patrol trooper shot and killed a 30-year-old Port Orchard man alleged to have attacked him in his yard Saturday night.

Cpl. Jason Blankers, 36, told investigators with the Kitsap County Sheriff’s Office he noticed a vehicle enter his driveway on the 8000 block of SE Nelson Road, near Olalla, at about 11:27 p.m., according to a statement from the office.

Blankers told a family member to call 911, walked outside with a handgun and identified himself as law enforcement, the statement said.

“Almost immediately, (Blankers) became engaged in a struggle with the intruder” where the suspect struck Blankers in the head with a metal rod, knocking him to the ground.

Blankers ordered the suspect to stop and then shot the man. The suspect was treated at the scene and was taken to Tacoma General Hospital, where he was pronounced dead.

Deputy Scott Wilson, a spokesman for the Kitsap Sheriff’s Office, identified the suspect as Brent Richard Bayliffe. Wilson said there are no known connections between the men.

The Pierce County Medical Examiner will determine cause of death. Additionally, the office will conduct toxicology tests.

Wilson wouldn’t say if there were other witnesses beside Blankers, saying that information has not been made public. After the investigation is complete, the office will forward a report to prosecutors for review.

“The ‘why’ is not one of the questions that may be answered adequately or fully,” Wilson said of Bayliffe’s motivation. “We can’t talk to him.”

Blankers, an emergency driving instructor at the State Patrol’s academy in Shelton, has been with the patrol for 11 years, according to a statement. He has never been involved in a deadly shooting before. He was placed on administrative leave while the sheriff’s office investigates.