BELLINGHAM, WA (MyBellinghamNow.com) – The trial is underway for a Seattle man accused of killing his brother in North Cascades National Park.

42-year-old John Thomson is charged with first degree murder in the killing of his 69-year-old brother near Diablo Lake in August 2022.

Court documents state that the brothers went to their cabin in Republic so John could detox from heroin and alcohol. John told detectives that his brother was beating and belittling him on the ride back, when he decided that he’d had enough and shot Robert in the back of the head.

John says he shot his brother 20 times before throwing him down an embankment.

He pleaded not guilty, and the Bellingham Herald reports that his attorney argues Thomson was acting for fear of his own life.

Thomson is a previously convicted felon and has also been charged with unlawful firearm possession in addition to murder.

His trial began in Whatcom County Superior Court earlier this week and will continue on Monday.