A group of anti-Trump demonstrators used gas canisters, rocks and bottles to assault police Tuesday night and create havoc at what officials said was mostly a peaceful protest in Phoenix. Video captured by a local reporter also shows a smoking object being thrown at police while hundreds of officers attempted to keep order at a rally after President Trump's speech at the Phoenix Convention Center had ended. Video appears to show demonstrators throw canisters at police pic.twitter.com/inNJoCf82V