Washington County sheriff's Sgt. Bob Ray says deputies arrested a 25-year-old man after the neighbors returned home Tuesday and found both the note and the bullet hole.
The Oregonian reports that Ray says the man was showing a friend the safety features on two firearms on Sunday when he accidentally fired a .45-caliber handgun. The bullet went through the wall of his apartment and into a neighboring unit.
Ray says Malcolm K. Smith was arrested for investigation of reckless endangering.
The spokesman says the right thing to do is to notify authorities immediately so they can check to see whether anyone has been hurt. In this case, no one was.