(Portland, OR)  --  A man is facing charges after allegedly punching a Portland Police officer in the face during an investigation into a traffic crash.  Police say it happened Wednesday morning near Northeast 94th and Halsey.  Prior to the officer's arrival, the driver walked away, but police say he then returned to the scene and became agitated.  When officers tried to detain the driver, he allegedly punched the officer in the face.  Police arrested 26-year-old Alexander York of Portland.