The man suspected of shooting conservative commentator Charlie Kirk wrote saying he has "the opportunity to take [him] out."

According to FBI director Kash Patel, the note was found in the home of Tyler Robinson reading: "I have the opportunity to take out Charlie Kirk and I'm going to take it."

Mr Robinson, 22, remains in custody and is set to be formally charged with the murder tomorrow, Tuesday.

According to Mr Patel, the note was written before the shooting, having been found "in the suspect's home."

Charlie Kirk was shot at the Utah University

Tyler Robinson, 22, remains in custody

Mr Patel said: "We have since learned the note, even though it was destroyed, we have found forensic evidence of the note and we have confirmed what the note said because our aggressive interview posture at the FBI."

Charlie Kirk was killed by a single rifle shot during the event attended by 3,000 people in Orem, about 40 miles south of Salt Lake City.

Utah Governor Spencer Cox said Mr Robinson "is not cooperating, but all the people around him were cooperating, and I think that's very important."

One person who is apparently talking to investigators is Robinson's roommate, who was also a romantic partner, Cox said, citing the FBI.

Republican Governor of Utah Spencer Cox made the announcement | GB NEWS

Charlie Kirk was shot while giving a speech at Utah Valley University | GETTY

Cox described the roommate as "a male transitioning to female," and said the roommate has been "incredibly cooperative."