“The Anacortes man who drove a three-man, drunken shooting spree across Skagit County that resulted in the high-profile murder of a Navy junior officer killed himself in a state prison last week.Seth Anderson hanged himself with bed linen in Walla Walla State Penitentiary Jan. 2, according to Walla Walla Police Department Sgt. Matt Wood. Anderson was taken off life support two days later. He was 23 years old.Anderson, along with his half-brother, 36-year-old Eben Berriault, pleaded guilty to first-degree murder to avoid the death penalty in the shooting death of 23-year-old Navy Lt. jg Scott Kinkele last July. Anderson started serving his 38-year-and-nine-month sentence last November.Wood said Anderson had been placed in a one-man segregation cell because he had been fighting with other inmates. A guard who was handing out mail found Anderson, Wood said, hanging by the neck from a homemade noose made from a sheet.The guards cut Anderson down and immediately performed CPR, but he never regained consciousness. His family went to the hospital and took him off life support after consulting with doctors Jan. 4.Wood said he’s waiting for the coroner’s report to officially close the case, but he has no reason to believe the death was anything but a suicide.The guards check all the inmates on a regular basis, Wood said, but they had no reason to suspect that Anderson was suicidal.Anderson’s sister, Grace Anderson, described her brother as an animal-lover who drove horse-drawn carriages at the Skagit Tulip Festival when he wasn’t fishing in Alaska. She said he quit a job driving carriages in San Francisco because he didn’t like the way the company was treating the horses. When he has time, he helps out an elderly man on a ranch near Sedro-Woolley.Seth was going to buy a house with horses, she said.Berriault’s criminal history included a manslaughter conviction in Chelan County, but Anderson record was clean. Berriault is serving a 55 year sentence and won’t be eligible for parole until he’s 85 years old. Investigators believe Anderson was driving the night of the murder. Berriault leaned out of the car and shot Kinkele – who was driving home to the Whidbey Island Naval Air Station – in the back of the head with a slug from a shotgun. The third man involved in the shooting, 26-year-old Adam Moore, pleaded guilty to second-degree manslaughter and was sentenced to two years and three months in prison last month. He was in the back seat during the shooting and cooperated with investigators about the murder.Both Anderson and Berriault claimed that Moore was the real shooter. “