The quiet town of Butler, Pennsylvania was shattered by a tragic act of violence on Saturday evening as an armed gunman opened fire on a campaign rally for former President Donald Trump. In the chaos that ensued, firefighter Corey Comperatore was killed while bravely trying to shield his family from the hail of bullets, according to CNN. Authorities have identified the shooter as 20-year-oldThomas Matthew Crooks, a resident of the nearby town of Bethel Park. Want more breaking political news? Click for the latest headlines at Raw Story. Crooks, perched on a rooftop outside the rally venue, fir…