A veteran whose team holds the world record for longest confirmed sniper kill claims Donald Trump's shooter 'had help' in his attempted assassination attempt. Dallas Alexander, who spent 14 years in a sniper team for the Canadian military doing close protection for major world leaders including the Canadian prime minister, suggested in a video Thomas Matthew Crooks, 20, who opened fire at the former president's rally Saturday night, may have had help from the inside. 'I'm very familiar with the layout of these types of things and what the job should be, and yesterday what happened,' he said.