Charges dismissed against man who killed a husband and wife on the Key Peninsula

Cory Nathan Mason told investigators last year that he killed a husband and wife on the Key Peninsula in self-defense.

Prosecutors told the court Friday that they can’t prove otherwise beyond a reasonable doubt, and the second-degree murder charges against the 28-year-old were dismissed.

Mason fatally shot 35-year-old Lukas Slawson and 25-year-old Beth Hamlin-Slawson Feb. 3, 2018 outside a home in the 5500 block of Whiteman Road.

He called 911 after the shooting and told officers it was self-defense.

“Washington law on self-defense provides a killing is justified if a defendant reasonably feared imminent death or great personal injury at the time of the killing,” deputy prosecutor Kawyne Lund wrote in her motion for dismissal. “A defendant is entitled to act on what he perceives and at the time believes in good faith and on reasonable grounds, that he or another is in actual danger, even if afterwards it is learned he was mistaken as to the extent of the danger.”

According to charging papers:

Mason and Hamlin-Slawson were upset with each other over a gun sale and a domestic-violence incident that allegedly involved Mason and Hamlin-Slawson’s sister.

Slawson, his wife and Mason arrived about the same time at the Whiteman Road residence, where Mason and the sister were living.

Hamlin-Slawson got out of her car with a sledge hammer and hit Mason’s vehicle.

Someone grabbed the hammer from her, and Mason drove a short distance away.

Then Slawson started shooting at a different vehicle on the property, while Hamlin-Slawson and Mason argued.

Mason shot Hamlin-Slawson in the chest when he heard gunshots. She had been approaching him, and he thought she might be shooting at him, he said.

“Given the lack of lighting, the speed at which the events occurred, (Hamlin-Slawson’s) aggressive focus on the defendant, and that the defendant had been in the car when (Hamlin-Slawson) was disarmed, the state cannot show beyond a reasonable doubt the defendant knew at the time he fired that (Hamlin-Slawson) had been disarmed” of the hammer, Lund wrote in her motion for dismissal.

Then Mason shot Slawson in the chest, he told investigators, when he saw him approaching with a gun.

Lund wrote that a witness reported standing between them, because she was worried Slawson would shoot Mason. Video shows Slawson point his gun at Mason, then shows Slawson running to the house with a gunshot wound, Lund wrote.

“Therefore, in consideration of the facts stated, including evidence not previously available, i.e. the video (recently enhanced), recent witness interviews done for trial, and the 911 calls, and the applicable law, the Pierce County Prosecutor’s Office has concluded the State cannot disprove the element of self-defense beyond a reasonable doubt as required by law,” the motion says.

This story was originally published April 2, 2019 at 4:44 PM.