Authorities are investigating the motive behind an assassination attempt on former President Donald Trump at a Pennsylvania rally. The shooter, Thomas Matthew Crooks, was killed by the Secret Service. One victim, Corey Comperatore, was killed, and two others, David Dutch and James Copenhaver, are in stable condition. President Joe Biden condemned the violence, urging Americans to reject political violence. The FBI is leading the investigation but has not yet identified a motive.