[Source: Reuters]

U.S. investigators said on Thursday they had found the bolt-action rifle they believed was used to kill the influential conservative activist Charlie Kirk and released images of a person of interest as they searched for the shooter they described as college age.

Kirk, a 31-year-old author, podcast host and close ally of U.S. President Donald Trump, helped build the Republican Party’s support among younger voters. He was killed on Wednesday by a single gunshot as he gave a talk at a university in Utah in what Trump called a “heinous assassination.”

FBI and state officials said the killer arrived on the campus a few minutes before the event began, a debate led by Kirk titled “Prove Me Wrong” outdoors in front of about 3,000 people at Utah Valley University in Orem, Utah, about 40 miles (65 km) south of Salt Lake City.

Security-camera videos show a person going up stairwells to get onto a roof before firing at Kirk, the officials told a press conference. Kirk, a staunch defender of gun rights, was answering an audience question about mass shootings when the bullet struck his neck. Audience members fled in panic.

The shooter jumped off the roof and fled into an adjoining neighborhood, Robert Bohls, the FBI special agent in charge, told reporters.

Investigators found a “high-powered, bolt-action” rifle in a nearby wooded area, and were examining that along with palm prints and footprints for clues. On Thursday, with classes canceled, the roof of the building on the otherwise deserted campus and the nearby woods were strung with yellow tape as investigators scoured them for evidence.

The shooter appears to be of college age and “blended in well” on the campus, Utah Public Safety Commissioner Beau Mason told reporters.

The shooter has not been publicly identified, but the FBI circulated grainy images apparently taken from security cameras showing a “person of interest” wearing a black top, black sunglasses and a dark baseball cap. The top appears to have an image of a bald eagle flying across a U.S. flag.

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