 So close to former President Donald Trump at his rally in Butler, Pennsylvania, Saturday. The second investigation is into the 20-year-old shooter, who the FBI says acted alone. I'm joined now by our CBS News correspondent, Meg Oliver, who is in Pittsburgh, outside of the hospital where two shooting victims are being treated, and our Homeland Security and Justice correspondent, Nicole Skanga. Nicole, I want to start with you. What are we learning? What do we know about the investigation into the shooting?