Many questions remain following an assassination attempt on former President Donald Trump, who was injured when shots rang out at a campaign rally in Pennsylvania on Saturday. 

A rally attendee was killed and two others were seriously injured. The attack happened days before Trump will officially be nominated to lead the Republican ticket at the Republican National Convention. 

NY1's Rocco Vertuccio spoke with Dr. David Green, a political science professor at Columbia University, about how the campaign is responding.