Charlie Kirk's alleged killer is not cooperating with authorities and has not confessed to carrying out the shooting, Utah's governor Spencer Cox has told US media.

Suspect Tyler Robinson, 22, was taken into custody some 33 hours after Kirk, a 31-year-old right-wing activist, was shot dead in Orem on Wednesday. Speaking to ABC News, Cox, a Republican, said people around Mr. Robinson had been cooperating with the investigation. Cox appeared on various US news outlets on Sunday morning, where he also reiterated concerns regarding social media in the aftermath of Kirk's death.

The governor was asked about a New York Times report alleging Mr. Robinson had spoken to others after the shooting via the Discord messaging platform, including allegations that he joked about being the gunman. Cox confirmed that those conversations had occurred, but the people involved did not believe it was actually him at the time.

Mr. Robinson was arrested after surrendering to police on Thursday night, following Kirk's shooting during an open-air event at Utah Valley University held by Turning Point USA, an organization co-founded by Kirk. Cox previously stated that Robinson was deeply indoctrinated with leftist ideology based on information from the suspect's friends and family.

Amidst the investigation, it has been confirmed that Robinson's partner has been cooperating fully with authorities, though Cox acknowledged uncertainty regarding how this might pertain to the case. An affidavit confirms that Mr. Robinson is being held on suspicion of aggravated murder, felony discharge of a firearm, and obstruction of justice.

In light of Kirk’s death, Governor Cox has been calling for unity within the community to ease political tensions and has made several comments criticizing the role of social media in exacerbating these issues. Kirk’s widow, Erika, has also expressed her intent to keep her husband's legacy alive following the tragedy. A memorial service for Kirk is scheduled for 21 September at the State Farm Stadium in Arizona.