(Portland, OR)  --  Police say they've arrested a man seen on surveillance footage driving onto a sidewalk and hitting at least two pedestrians in northeast Portland.  Police arrested 21-year-old Austin Keever-Nyberg yesterday after he turned up at the Clackamas County courthouse for an unrelated matter.  Police say a home surveillance camera caught him accelerating toward three people walking on a sidewalk January 10th, striking at least two of them.  He then appears to pursue the group in his pickup truck.  He's now facing charges of first-degree attempted assault.