The man suspected of fatally shooting right-wing political activist Charlie Kirk has been charged with aggravated murder.
Tyler James Robinson is accused of shooting Mr Kirk on the campus of Utah Valley University in Orem on September 10.
He has also been charged with discharging a firearm, as well as multiple counts of obstruction of justice, witness tampering and committing a violent act in the presence of children.
Utah County Attorney Jeff Gray told a press conference on Tuesday, local time, that prosecutors would seek the death penalty.
Mr Gray said he had made that decision "independently, based solely on the available evidence and circumstances and nature of the crime".
"The murder of Charlie Kirk is an American tragedy," he said.
"Charlie Kirk was murdered while engaging in one of our most sacred and cherished American rights, the bedrock of our democratic republic, the free exchange of ideas and a search for truth, understanding and a more perfect union."
Mr Robinson was being held without bail after turning himself in on Thursday after a family friend met with him and his parents and convinced him to do so, prosecutors said.
Prosecutors give more details on case
Prosecutors allege that the gun investigators found had Mr Robinson's DNA on it.
They also allege he deliberately tried to hide the weapon and the clothes he wore on the day.
It is also alleged that Mr Robinson told his roommate, who Utah Governor Spencer Cox had previously identified as a romantic partner, that he had killed Mr Kirk because he had "enough of his hatred" and that "some hate can't be negotiated out".
Mr Gray added that in another message, he told his roommate: "Drop what you're doing, look under my keyboard."
There was allegedly a note under the keyboard that read: "I had the opportunity to take out Charlie Kirk, and I'm going to take it."
It was said the roommate responded by saying: "What? You're joking."
Mr Robinson also allegedly told his roommate to delete texts related to the shooting.
Authorities had previously said the roommate was transgender and transitioning from male to female.
It was unclear whether the accused had an attorney who could speak on his behalf, and his family declined to comment to The Associated Press.
Mr Gray added that the accused was innocent until proven guilty by a jury.
Mr 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.
A polarising figure, he often posted carefully edited clips of his interactions during debates at his many college events.
FBI director Kash Patel has been heavily criticised for his actions in the immediate aftermath of the shooting, including having quickly announced the arrest of a separate suspect, only to confirm they had been released 2 hours later.
Mr Patel faced a grilling from a Senate panel on Tuesday that included some very bad-tempered exchanges with Democratic senator Corey Booker.
The FBI chief has come under fire from both the right and the left since being named by US President Donald Trump to head the FBI, the nation's premier law enforcement agency.
On Monday, the White House said it would be pursue an alleged left-wing "domestic terror movement" in the wake of Mr Kirk's killing, prompting alarm that such a campaign could be used to silence political dissent.
ABC/wires
