GRESHAM, Ore. -- The suspect in the murder of a 19-year-old Gresham man told police he shot the victim, but he said the victim tried to stab him with a knife before he shot him, according to a court affidavit.

Jamaine Oliver Jr., an 18-year-old Fairview man, was arrested Friday and booked into the Multnomah County Jail on a charge of first-degree murder. According to the affidavit, the victim, 19-year-old Christopher Moss Jr., of Gresham, died from a single gunshot wound to the back,

Officers were called out to an abandoned Walgreen's store at Northeast 162nd Avenue and Glisan Street on Thursday, Oct. 27, at about 10:22 p.m., where they found Moss, who was taken to the hospital and later died.

Court documents indicate that Oliver and Moss got into an argument, after which Oliver chased Moss and shot him once in the back. There were three witnesses to the shooting, one of whom identified Oliver as the shooter from a photo lineup.

Anyone with information should call the Gresham Police at 503-618-2719. An investigation is ongoing.