 Live from NPR News in Washington, I'm Dave Mattingly. The FBI says it believes the 20-year-old gunman who tried to assassinate former President Donald Trump at a rally in Pennsylvania on Saturday acted alone. The gunfire grazed Trump's right ear and left one rally attendee dead and two others wounded. Authorities shot and killed the gunman, who was situated on a rooftop outside the venue in the city of Butler, north of Pittsburgh.