(Portland, OR) -- Portland Police say they arrested a prolific graffiti vandal on Thursday. Officers received a report of a suspect spray painting graffiti in what's called a "bombing run." That's when the suspect spray paints as much graffiti as possible while moving through an area. Officers spotted the suspect near Southeast 6th and Madison. After a brief chase, 18-year-old Aiden Rivero, of Beaverton, was arrested. He allegedly uses the tagger name "GEM" which has been painted at least 20 times. Police recovered spray paint and other evidence. Rivero will be charged with criminal mischief and escape.