The suspect was arrested at 22:00 on Thursday, local time, says FBI chief Kash Patel.
This would not have been possible without you in the media and you in the general public, and that's why we have been so transparent about the investigation, he says and adds that they have received over 11,000 tips.
The suspect hinted after the murder to relatives that he was involved in the shooting, says Utah Governor Spencer Cox.
Expressed himself hatefully
The arrest could be made after a relative of Robinson contacted a friend of the family, who in turn contacted the authorities and informed them of Robinson's confession, adds Cox.
Robinson is said to have become increasingly politically engaged in recent times, and specifically expressed himself negatively about Kirk, family members have further told the police, according to Cox.
I want to thank Tyler Robinson's family for their actions, says Cox and names the father, mother, and sister.
The authorities have also spoken with a roommate of the suspect who showed them a social media conversation with a user named "Tyler", according to Cox. The messages mentioned a rifle left in a green area.
Political message
Several messages were engraved on cartridges found with the suspected murder weapon, including "Hello fascist! Take this!", says Cox.
Among the evidence is also surveillance footage showing how Robinson arrived at Utah Valley University on the morning of the day of the murder.
He is suspected of acting alone.
This is a very sad day for our country, a terrible day for Utah, but right now I'm glad that we have an opportunity to get a closure on this dark chapter in our nation's history, says Cox.
Trump first out
The news of the suspect's arrest came first from Donald Trump.
I hope that Kirk's murderer is convicted and gets the death penalty, said Trump to Fox News.
Governor Cox has previously said that the state will seek the death penalty when the suspect is prosecuted.
During the night towards Friday, the police authority in Utah released a surveillance video of a person "of interest" after the murder. In the clip, the person is seen running over a roof and then jumping down to the ground, before running from the scene.
Charlie Kirk was shot dead while speaking in front of a large crowd at Utah Valley University on Wednesday.
Corrected: In an earlier version of the text, an incorrect translation of "casings" was used.
Mattias Mächs/TT
Martin Yngve/TT
Facts: Charlie Kirk
TT
31-year-old Charlie Kirk was shot dead while speaking in front of a large crowd at Utah Valley University on Wednesday, American time.
The father of small children has been described as a superstar within the American right and was close to President Donald Trump, and it was Trump who a few hours after the shooting announced via social media that Kirk was dead.
At the age of 18, Kirk co-founded the conservative student organization Turning Point USA and is said to have been a contributing factor to why so many young Americans voted for Trump in last year's election.
His casket was taken to Phoenix in Arizona on Thursday with the help of Air Force Two, the American vice president's plane. On board were Kirk's widow and Vice President JD Vance.
Charlie Kirk will posthumously be awarded the United States' highest honor for civilians, announced Trump on Thursday.
