The gunman who opened fire at a Donald Trump rally had explosives in his car, US media reported Sunday, as investigators probed the attempted assassination of the Republican presidential candidate.The Wall Street Journal and CNN said that explosive materials were found in a car belonging to shooter Thomas Matthew Crooks, which was reportedly parked near the campaign event venue in Butler, Pennsylvania.Former vice president Mike Pence said Sunday that “there is no place in America for political violence” of the sort that targeted his former boss at a Republican rally.Such violence, Pence…