Zachary Brimhall's father, 58-year-old William Ray Brimhall of Dillard, Oregon, had been shot multiple times, Coos County District Attorney Paul Frasier said. The older man's body was found Tuesday near his vehicle on a remote logging road in the Coast Range about 50 miles from Bastendorff Beach, where the drive-by shooting took place earlier in the day.
"No question the son is responsible" for his father's death, Frasier said in a telephone interview late Tuesday. Investigators don't yet know what set off the violence, the prosecutor said.
Zachary Brimhall's mother told investigators that her husband left home Monday after their 34-year-old son called to say his car had broken down at a remote Coos County campsite and he needed help.
It appears the older man was killed shortly after he reached the campsite Monday night, Frasier said.
Investigators think the son then drove to the beach and several hours later started shooting, the prosecutor said. The first 911 calls from the beach came in at about 1 a.m. Tuesday.
Asked about a motive, Frasier said, "That's the big question. We don't know.
"We're hoping to be able to find out. We may not."
Frasier said authorities believe Zachary Brimhall shot and killed David Jesse Hortman, 43, of Walker, Michigan, at the beach before killing himself. No one else was injured at the beach, the prosecutor said.
Investigators found several firearms, some large firecrackers used to frighten seals, and materials to make an improvised explosive device in Zachary Brimhall's vehicle and called the Oregon State Police bomb squad, Frasier said. Bomb technicians found no explosives in the father's vehicle.
Authorities said Hortman represented a recreational vehicle supply company and had decided to stay for a week of vacation after exhibiting at a trade show.
Mark MacPherson, whose car was also shot, told KCBY he thought someone was throwing rocks at his vehicle, "but my window shattered and I knew in that instant someone was shooting at me."
There was no known connection between Hortman and Zachary Brimhall, authorities said.
Bastendorff Beach just south of Coos Bay has long been a popular spot for homeless people as well as people who want to have a campfire on the beach.
About a year ago, the federal Bureau of Land Management cut maximum camping time from 14 days to 24 hours at the site and stepped up patrols due to problems.
"We have had some problems in the past with some nefarious activity out there," agency spokeswoman Megan Harper said. "We have tried to step up patrols lately and it had seemed like it was getting a lot better."
Dillard Store & Deli owner Keith Sjogren said Ray Brimhall had worked at a wood products mill and lived near the store, though Sjogren had not seen him for about six months. Sjogren described him as an easygoing man.