PROVO, Utah — Prosecutors are preparing to file a capital murder charge Tuesday against the Utah man who authorities say held a “leftist ideology” and may have been “radicalized” online before he was arrested in the assassination of Charlie Kirk.

Charges against 22-year-old Tyler Robinson are expected to come ahead of the first court hearing since he was accused last week of shooting Kirk, a conservative activist credited with energizing the Republican youth movement and helping President Donald Trump win back the White House in 2024.

Investigators have been piecing together evidence, including a rifle and ammunition engraved with anti-fascist and meme culture messaging, found after the shooting Wednesday at Utah Valley University in Orem. Kirk was speaking there on one of his many campus visits where he relished debating just about everyone.

Prosecutors in Utah County are considering several charges against Robinson, the most serious being aggravated murder because it could bring the death penalty if there is a conviction.

Once charges are filed, Robinson is scheduled to appear on camera for a virtual court hearing. He has been held without bail since his arrest, and it remained unclear whether he has an attorney.

While authorities say Robinson hasn’t been cooperating with investigators, they do say his family and friends have been talking. Utah Gov. Spencer Cox said over the weekend that those who know Robinson say his politics shifted left in recent years and that he spent a lot of time in the “dark corners of the internet.”

FBI Director Kash Patel said Monday on the Fox News show “Fox & Friends” that DNA evidence has linked Robinson to a towel wrapped around a rifle found near the Utah Valley campus and a screwdriver recovered from the rooftop where the fatal shot was fired.

Before the shooting, Robinson wrote in a note that he had an opportunity to take out Kirk and was going to do it, according to Patel.

Investigators are working on finding a motive for the attack, Utah’s governor said Sunday, adding that more information may come out once Robinson appears for his initial court hearing.

Cox said Robinson’s romantic partner was transgender, which some politicians have pointed to as a sign the suspect was targeting Kirk for his anti-transgender views. But authorities have not yet said whether that played a role. Kirk was shot while taking a question that touched on mass shootings, gun violence and transgender people.

Utah Department of Public Safety Commissioner Beau Mason said Monday that Robinson’s partner has been cooperative. He said investigators believe Robinson acted alone during the shooting, but they also are looking at whether anyone knew of his plans beforehand.

In the days since Kirk’s assassination, Americans have found themselves facing questions about rising political violence, the deep divisions that brought the nation here and whether anything can change.

Despite calls for greater civility, some who opposed Kirk’s provocative statements about gender, race and politics criticized him after his death. Many Republicans have led the push to punish anyone who they believe dishonored him, causing both public and private workers to lose their jobs or face other consequences at work.

Seewer reported from Toledo, Ohio.

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