(Portland, OR)  --  Police in Portland say they have arrested an 18-year-old man on gun charges after he allegedly fired a pistol in a Northeast Portland neighborhood.  Police arrested Bennet P. Miller after reports of gunshots early yesterday morning near Northeast 93rd Avenue.  Police found a gun in the bed of a truck shortly after talking to Miller.  Miller was arrested and charged with discharging a firearm in the city.  No one was injured.