Pennsylvania GOP activist who’s been to 20 Trump rallies says Butler event was least secure venue he’s been to Fox NewsLive updates: Trump rally shooting investigation continues after assassination attempt CNNSecret Service spotted Trump rally shooter on roof 20 minutes before gunfire erupted ABC NewsA Blind Spot and a Lost Trail: How the Gunman Got So Close to Trump The New York TimesOpinion | Incivility and the Tragedy of the Commons The Wall Street Journal