A knife-wielding Portland, Oregon man was arrested Monday after he hid for hours in the rafters of a Target store following a confrontation with a security guard, police said.Officers responded around 10:30 a.m. to reports of a disturbance involving a weapon at the Target in the 9800 block of Southeast Washington Street, according to the Portland Police Bureau.Witnesses initially told police that a suspect armed with a knife and a hatchet threatened a security guard before fleeing deeper into the store.The security officer received medical treatment at the scene.KNIFE ATTACK AT MASSIVE PORTLAND RAVE LEAVES FOUR TEENAGERS WOUNDEDPolice evacuated the building and launched a search. They eventually spotted the man armed with a knife and perched on a second-story shelving unit used to store excess inventory in the back of the retailer.Officers negotiated with the suspect for several hours. He eventually dropped the knife and surrendered around 4 p.m., police said.The man was identified as Michael Harper, 41, of Portland. He was booked into the Multnomah County Detention Center on charges of assault, attempted assault, and unlawful use of a weapon.