SALEM, Ore. (AP) — Lawyers for an Oregon hunter who killed a man he mistook for a bear say they concede their client shot the Marine reservist, but they maintain the death in a field near Silver Falls State Park was an accident.

The defense says 68-year-old Eugene Irvin Collier was "100 percent sure it was a bear" he was firing at while hunting with his 12-year-old grandson on private land in October 2011. But the prosecution argues Collier recklessly killed the 20-year-old California man who had crossed the property on what he thought was a shortcut to the state park.

Collier's trial on a manslaughter charge began Tuesday, and lawyers say it will center on whether the shot that killed Christopher Ochoa was reckless or accidental.

"It's conceded that Eugene Collier caused the death of Christopher Ochoa," defense lawyer Jeff Jones said.

Collier, from nearby Turner, was hunting with his grandson on land owned by Collier's brother.

Prosecutor Toby Tingleaf said Ochoa had come to Oregon from French Camp, Calif., to help a friend.

The two decided to take a shortcut to Silver Falls State Park. They crossed a road and entered a 100-acre field of grass, Tingleaf said.

"One sign said no hunting," Tingleaf said. "They didn't realize they weren't on state property."

Collier fired his rifle at what he thought was a bear, Tingleaf said, but he didn't have a state tag to hunt bears.

"This case is about Christopher Ochoa," the prosecutor said. "His death is not accidental. It should have and could have been avoided."

Jones said the property had a bear problem, and Collier's family rarely saw trespassers. Continued...