WASHINGTON, United States (AFP) – DNA found at the scene of the murder of United States (US) conservative influencer Charlie Kirk has been matched to suspect Tyler Robinson, Federal Bureau of Investigation (FBI) Director Kash Patel said Monday.

Robinson, 22, was arrested Thursday after a 33-hour manhunt and is expected to be formally charged in the murder later this week.

Kirk, a close ally of US President Donald Trump, was shot Wednesday during a speaking event on a Utah university campus. He was the founder of the hugely influential conservative youth political group Turning Point USA.

Authorities said the suspect used a sniper rifle to shoot Kirk with a single bullet to the neck from a rooftop.

“I can report today that the DNA hits from the towel that was wrapped around the firearm and the DNA on the screwdriver are positively processed for the suspect in custody,” Patel said on Fox News Monday morning, referring to a screwdriver recovered from the scene.

Patel also discussed a note that Robinson is believed to have written before the crime.

The note is “basically saying… ‘I have the opportunity to take out Charlie Kirk, and I’m going to take it.’ That note was written before the shooting,” Patel said.

He added that note was left at the suspect’s family home.

“Even though it has been destroyed, we have found forensic evidence of the note,” the FBI director said.

Kirk, a father of two, used his audiences on TikTok, Instagram and YouTube to build support for conservative talking points, including strong criticism of the transgender rights movement.

He often posted carefully edited clips of his interactions during debates at his many college events.

US President Trump will attend a memorial service on Sunday at a stadium in Arizona. His vice president, JD Vance, hosted Kirk’s podcast on Monday.

The alleged murderer was a brilliant high school student raised in the Mormon faith by Republican parents and is expected to be charged on Tuesday by Utah authorities.

Utah Governor Spencer Cox said Robinson was romantically involved with a transgender roommate and had “leftist ideology.”

FBI Deputy Director Dan Bongino — also a prominent right-wing podcast host, appointed to the FBI under the Trump administration — said the suspect had shown “intent” before the attack.

“There appear to have been multiple warning signs,” he told Fox News on Monday.

Bongino cited friends and family members who said the suspect had become “more political.”

FBI Director Patel has been heavily criticised for his actions in the immediate aftermath of the shooting, including having announced the arrest of a suspect a few hours after the shooting.

Two hours later, he confirmed that that person had been released.

On Monday, Patel defended his actions.

“Could I have worded it a little better in the heat of the moment? Sure. But do I regret putting it out? Absolutely not,” he told Fox News.

Patel is expected at Congress on Tuesday to answer questions from lawmakers.