Key Points

Tyler Robinson was turned in by his father, who recognised his photographs circulated by law enforcement and had heard him making radical statements, Trump said without naming him on Fox News before Cox’s announcement.

"And the father convinced the son, 'this is it’”, he said.

Kirk, a conservative youth leader with a large following, was shot dead on Wednesday when he was speaking at a university in Utah.

Trump attributed his victory last year to Kirk mobilising young people to vote for him, and he emerged as an adviser to Trump.

Kirk was close to Vice President JD Vance and had lobbied with Trump to make him his running mate.

Cox, who identified Robinson, said at a news conference with Federal Bureau of Investigation Director Kash Patel at his side in Salt Lake City, "The family member referenced a recent incident in which Robinson came to dinner prior to September 10, and in the conversation with another family member, Robinson mentioned Charlie Kirk was coming to” the Utah Valley University (UVU).

"They talked about why they didn't like him and the viewpoints he had,” he said.

Robinson’s father told his priest about him after recognising him in the photographs, and he contacted law enforcement.

He was arrested without incident.

Cox and Trump have said that they would seek the death penalty for Robinson.

Utah is the only state which has provisions for a firing squad to carry out executions.

Kirk was invited to UVU by its chapter of Turning Point USA, the conservative youth group he founded.

Utah officials on Thursday released video of the assailant jumping off the roof of a building and running away towards a wooded area, where they later retrieved the gun used in the shooting.

Kirk's killing was the latest in the tide of political violence in the US.

The trial is continuing on Friday of the man who is charged with trying to assassinate Trump last year after the then-presidential candidate had narrowly escaped another attempt with a slight injury.

In June, a man assassinated the former speaker of the Minnesota House of Representatives and her husband.

In April, an assassination attempt was made on Pennsylvania Governor Josh Shapiro by setting his residence on fire.

Last month, a transgender person opened fire at a Catholic school in Minnesota, killing two children.

- IANS