WASHINGTON (AP) — The 20-year-old nursing-home employee from suburban Pittsburgh who tried to assassinate former President Donald Trump was a registered Republican who packed explosives in the vehicle he drove to the campaign rally an hour from his home. Law enforcement officials were working Sunday to learn more about Thomas Matthew Crooks of Bethel Park, Pennsylvania, to determine what motivated him to open fire on the rally from a nearby rooftop, killing one spectator, before he was shot dead by the Secret Service. The FBI said Sunday it has not yet identified any threatening writing or social media posts from Crooks, who graduated from high school two years ago and had no past criminal cases against him, according to public court records. Trump, the presumptive Republican presidential nominee, said on social media the upper part of his right ear was pierced in the shooting. Two spectators were critically injured, authorities said. The man killed was Corey Comperatore, a former fire chief from the area who Pennsylvania’s governor says died a “hero” by diving onto his family to protect them. Relatives of Crooks didn’t immediately respond to messages from The Associated Press. His father, Matthew Crooks, told CNN late Saturday that he was trying to figure out “what the hell is going on” but wouldn’t speak about his son until after he talked to law enforcement. (Photo: AP)