The man accused of fatally shooting conservative activist Charlie Kirk has been identified as Tyler Robinson, 22, a Utah native who had been living with his parents for a long time, authorities said.

Robinson was taken into custody on 12 September after a family member recognised him in surveillance images, a development investigators described as pivotal in ending a nationwide manhunt.

That family member was apparently Robinson's father, who encouraged him to turn himself in, the BBC's US partner CBS News has reported, citing two law enforcement sources. The father then reportedly contacted a family friend who informed the sheriff's office.

At a press briefing on Friday announcing the arrest, FBI officials declined to discuss Robinson's background, political leanings, or possible motive, saying the investigation was ongoing.

We are confident we have the right individual in custody, an FBI spokesperson said, but we are still working to establish the full picture of who he is and why he acted.

Utah Governor Spencer Cox stated a family member interviewed by investigators indicated that Robinson had become more political in recent years.

The relative also mentioned that during a dinner conversation before the attack, Robinson had stated Kirk was full of hate and spreading hate and referenced Kirk's upcoming event at Utah Valley University.

Robinson's public records suggest he had in the past registered as an unaffiliated voter in Utah, while his parents are registered Republicans.

Investigators found that Robinson was deeply engrossed in online culture, with inscriptions on shell casings linked to the case displaying references to online trolling humor and potential sympathies to anti-fascist movements. One casing had the words Hey fascist! Catch! and others displayed phrases associated with gaming culture.

Currently, Robinson remains in custody as prosecutors prepare formal charges, while authorities continue their investigation into his background and the motivations for this politically charged incident.