Trump heads to convention as authorities investigate motive, security in assassination attempt

BUTLER, Pa. (AP) — Former President Donald Trump is calling for unity and resilience after an attempt on his life added fresh uncertainty to an already tumultuous presidential campaign. The shooting on Saturday also raised sharp questions about how a gunman was able to open fire from a rooftop near a Pennsylvania campaign rally. A full day after the attack, the gunman's motive was still a mystery, and investigators said they believe he acted alone.