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.
Mr 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 Mr 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 reached out to a family friend who contacted the sheriff's office.
At a press briefing on Friday announcing the arrest, FBI officials declined to discuss Mr 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 said a family member interviewed by investigators stated that Mr Robinson had become more political in recent years.
The relative also said that during a dinner conversation before the attack, Mr Robinson had stated Kirk was full of hate and spreading hate and mentioned Kirk's upcoming event at Utah Valley University, according to Cox.
Public records reviewed by the BBC suggest Mr Robinson had in the past registered as an unaffiliated, or nonpartisan, voter in Utah. Matthew Carl Robinson, the suspect's father, and Amber Denise Robinson, the suspect's mother, are registered Republicans, according to state records.
Mr Robinson was not enrolled at UVU, the site of the shooting.
Records reviewed by BBC Verify suggest he attended Utah State University in Logan for a single semester in 2021, possibly studying engineering. A photograph from that year shows him standing in front of the university's sign holding an acceptance letter.
Investigators say Mr Robinson was steeped in online culture, pointing to inscriptions on shell casings linked to the case.
Two casings displayed apparent references to online trolling humour. The inscription notices bulges OwO what's this? on a fired shell casing may refer to a copypasta - a piece of text that is repeated over and over again, often to troll people online. Another casing, that was unfired, was inscribed with the words If you read this, you are gay lmao - again an apparent reference to a trolling joke.
Meanwhile, other casings could be interpreted as sympathetic to Antifa, or the anti-fascist movement, a loose collection of far-left activists who have been active in the US over the last decade and often demonstrate against Trump policies and far-right groups.
One unfired casing had the words Hey fascist! Catch! and an up, right and three down arrows.
Authorities said Mr Robinson also appeared to have been active on Discord, the social media platform primarily used by gamers, but now also popular with other communities.
His roommate reportedly showed investigators a series of messages on Discord from a contact named Tyler referencing a rifle drop point and instructions about retrieving and hiding the weapon.
For now, Mr Robinson remains in custody as prosecutors prepare formal charges.
The investigation into his background, motives, and potential affiliations continues in what officials are calling one of the most significant political killings in recent US history.
