Provo (United States) (AFP) - The suspect in the killing of Charlie Kirk appeared in court Tuesday charged with the conservative activist’s murder, as prosecutors said they were seeking the death penalty for a crime that has shaken the United States.

Kirk, a close ally of President Donald Trump and the founder of student activism group Turning Point USA, was shot dead last week during an event on a Utah university campus.

The 31-year-old’s death prompted waves of mourning across the political right – and dark threats of retribution.

Tyler Robinson, 22, is accused of firing a single bullet from a rooftop, fatally hitting Kirk in the neck in front of thousands of people, in an episode that has deepened divisions in an already polarized country.

A huge manhunt ended 33 hours later when Robinson’s parents persuaded him to turn himself in after seeing photos of the wanted man.

Robinson wore a suicide prevention smock – common in high-profile cases – when he appeared in a Utah court Tuesday to hear the charges levied against him.

He spoke only to confirm his name and sat passively as District Judge Tony Graf read out the seven charges.

The most serious charge is aggravated murder, while others include obstruction of justice and witness tampering, allegedly for ordering his roommate to stay silent.

“I am filing a notice of intent to seek the death penalty,” Utah County Attorney Jeff Gray told an earlier press conference.

“I do not take this decision lightly, and it is a decision I have made independently as county attorney based solely on the available evidence and circumstances and nature of the crime.”

- Roommate texts -

The press conference, carried live on cable news channels across the nation, offered the first glimpse into possible motives for the alleged killer after days of fevered speculation that has consumed social media and dominated conversations.

Gray cited lengthy text message exchanges between Robinson and his roommate, whom he described as “a biological male who was transitioning genders.”

Robinson and the roommate were in a romantic relationship, Gray said.

Gray said on the day of the murder, Robinson had texted his roommate to say there was a message under his keyboard.

“I had the opportunity to take out Charlie Kirk and I’m going to take it,” said the note.

In one part of the exchange, the roommate, who was not named, asked Robinson why he had killed Kirk.

”‘I had enough of his hatred.’” Gray cited the messages as saying. “‘Some hate can’t be negotiated out.’”

He then tells the roommate to delete the exchange.

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 polarizing figure, he often posted edited clips of his interactions during debates at his many college events.

FBI Director Kash Patel has been heavily criticized for his actions in the immediate aftermath of the shooting, including having quickly announced the arrest of a suspect, only to confirm they had been released two hours later.

One of the two people initially arrested was charged Tuesday with possession of child pornography, in a development Utah County Sheriff’s office said was unrelated to Kirk’s killing.

On Monday, the White House said it would be pursuing an alleged left-wing “domestic terror movement” in the wake of Kirk’s killing, prompting alarm that such a campaign could be used to silence political dissent.