(Beaverton, OR)  --  No injuries are being reported, following a six-hour standoff in Beaverton.  Authorities say the suspect, 27-year-old Aaron Scott Barnes, pulled out a knife after deputies arrived at a Scholls Ferry Road apartment at two p.m. yesterday.  A tactical and crisis team was sent to the scene, and a flash-bang device was eventually sent into the apartment, allowing deputies to move in and arrest Barnes.  Officials say Barnes was wanted on a felony warrant for a parole violation.