Charlie Kirk, a conservative activist and close ally of President Donald Trump who played an influential role in rallying young Republican voters, was shot and killed Wednesday at a Utah college event in what the governor called a political assassination carried out from a rooftop. A person of interest was in custody, officials said.

'This is a dark day for our state. It's a tragic day for our nation," said Utah Gov. Spencer Cox. "I want to be very clear this is a political assassination.' Authorities did not immediately identify the person in custody, a motive or any criminal charges, but the circumstances of the shooting drew renewed attention to an escalating threat of political violence in the United States that in the last several years has cut across the ideological spectrum.