Officials: Ski Resort Shooter Killed Cat, Committed Suicide

The Nederland man who shot and killed a general manager at Eldora Mountain Resort killed himself after getting into a shootout with a deputy, the Boulder County coroner's office said.

The coroner's office said 24-year-old Derik Bonestroo, a ski lift operator at the resort, shot himself after being wounded during the gunbattle.

Officials previously said Boulder County Sheriff's Deputy John Seifert fired the shot that killed Bonestroo; however, the coroner's office said Wednesday that Bonestroo's death was ruled a suicide.

"Although the deputy wounded Mr. Bonestroo, the wounds did not cause his death," Coroner Thomas J. Faure said in a statement.

Authorities say Bonestroo shot Brian Mahon, 49, at the resort's pump house at about 7:30 a.m. Tuesday after yelling something about religion. Mahon was shot once in the stomach and once in the head and died at the scene.

Bonestroo then fled the resort, and was intercepted by Seifert on Colorado 119 just south of town. The coroner's office said Bonestroo was hit multiple times by the deputy's assault rifle before shooting himself.

Seifert was injured by flying glass and was treated at a hospital and released.

Also Wednesday, investigators said Bonestroo killed his cat before driving to the ski area with a gun. Boulder County investigators discovered the dead cat while searching Bonestroo's Nederland apartment to look for a motive behind his behavior.

Cmdr. Phil West said it wasn't clear if the cat was shot or stabbed, but said there was a lot of blood.

Meanwhile, one of Bonestroo's high school friends, Brent Hammans of Windsor, told The Daily Camera newspaper in Boulder that the slaying was a shock to those who knew Bonestroo.

Hammans, 24, played football with Bonestroo at Lyons High School five years ago, and described him as a "caring guy" who liked to hunt and was into sports.

"He was definitively calm and really smart," Hammans said. "He had a dry sense of humor, but he was funny."