POWELL, Wyo. (AP) — A criminal justice instructor at Northwest College has apologized for accidentally leaving his firearm in a classroom earlier this month.

Dave Patterson, who is a retired law enforcement officer, accepted full responsibility for the Oct. 14 incident in interviews with the campus and local newspaper and in an email sent to faculty and staff last week.

Patterson says he left his backpack with the gun inside after finishing with his Introduction to Criminal Justice class.

About 10 minutes later, he called Campus Security, which said his backpack had just been turned in by another instructor.

Patterson says he began carrying a gun in response to the Oct. 1 mass shooting at Oregon's Umpqua Community College.

Patterson is authorized to carry a concealed weapon.