(Tualatin, OR) -- A 16-year-old boy is facing charges after being accused of robbing a woman at knifepoint in Tualatin. Police say the robbery happened Sunday night between Cabela's and the Heron's Landing Apartments on Southwest Boones Ferry Road. A Washington County Sheriff's K-9 helped track down the boy and he was arrested. KOIN-TV reports the woman suffered minor scratches to her back.