Donald Trump has said he believes "with a high degree of certainty" that the shooter of Charlie Kirk is in custody.

The President told Fox News: "I think with a high degree of certainty we have him in custody".

Mr Trump added: "He's in custody" and that someone close to the suspect has turned him in.

The President said a "minister, father" helped in his capture, and the suspect is currently at police headquarters.

Charlie Kirk was killed earlier this week | GETTY

The Republican President said, if found guilty, he hopes the killer "gets the death penalty".

Mr Trump also said that it wasn't known whether the suspect was part of a bigger network, and that he did not want to watch the video of the shooting, adding that he did not want to remember Mr Kirk that way.

"I've never seen young people go to one person like they did to Charlie", the President said.

President Trump said Mr Kirk was "like a son" to him.

Charlie Kirk was a key ally of Donald Trump

Kirk, the co-founder and President of the conservative student group Turning Point USA, appeared at Utah Valley on Wednesday as part of a planned 15-event "American Comeback Tour" of US college campuses when he was shot.

His killing stirred outrage and denunciations of political violence from Democrats, Republicans and foreign governments.

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.

The shooter appeared to be of college age and "blended in well" on the campus, Utah Public Safety Commissioner Beau Mason said at the briefing.

Floral tributes have been laid outside Utah Valley University | REUTERS

A graphic showing the location of the shooting

Trump said the suspect in the killing of Mr Kirk is "28 or 29", contradicting earlier reports the shooter was "of college age"