Officers left post to go look for Donald Trump rally gunman before shooting, state police boss says

Crooks used a rifle and rangefinder to shoot at Trump at the July 13 Butler rally, after officers left posts. Secret Service Director Cheatle, citing this "most significant operational failure", resigned. District Attorney Goldinger and investigations seek Crooks' motive. House Oversight, Homeland Security Committees, bipartisan task force investigate. One death, two injuries.