Lawyers for accused Charlie Kirk assassin Tyler Robinson are arguing that prosecutors haven't established a case for the potential death penalty in a new court filing made public Tuesday night.
"The facts and the law require this Court to strike the sole aggravating factor," defense attorneys Kathy Nester, Michael Burt, Richard Novak and Staci Visser wrote in a 41-page brief.
After a week-long preliminary hearing in early July, Judge Tony Graf Jr. gave both sides in the case time to file briefs before he makes a decision on whether there is enough probable cause to send the case to trial — which he is expected to announce on Sept. 1.
Robinson, 23, is accused of shooting the 31-year-old Kirk at Utah Valley University on Sept. 10, 2025, during a Turning Point USA event. Kirk had founded the group to promote conservatism on campuses around the country and was speaking in front of a crowd of more than 2,000 in the courtyard when he was struck and killed by a single bullet.
Robinson's defense argued in Tuesday's filing that prosecutors didn't establish probable cause concerning the aggravating factor — that the shooting created a high probability of death to someone other than Kirk and that Robinson knew of that "high probability."
Without the aggravator, the potential death penalty would be taken off the table.
"The State had over ten months to investigate the shooting death of Charlie Kirk and to develop legally sufficient evidence that Mr. Robinson 'knowingly created a great risk of death to another other than Charlie Kirk and the defendant,' the sole aggravator alleged in the Information which in theory exposes Mr. Robinson to the potential punishment of death," Robinson's attorneys wrote. "The State’s presentation of its evidence as to this alleged circumstance in aggravation at the preliminary hearing in July 2026 wholly fails to carry its burden of proof."
Robinson's lawyers noted that there was only one shot fired and that it struck Kirk. No one else was hit.
They also argued that no one else was in the line of fire — noting that the bullet came from the rooftop, following a downward trajectory before striking Kirk.
"The only evidence presented supports that the bullet travelled above, not through, the crowd," they wrote.
When the suspected murder weapon was recovered, a .30-06 bolt-action Mauser rifle, there was a spent casing in the chamber and three unfired rounds.
And the evidence introduced by Utah County prosecutors indicates Kirk was the lone target, according to the defense filing.
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"The communications the State admitted between Mr. Robinson and Mr. Twiggs indicate Mr. Robinson’s intention to kill Charlie Kirk," the defense wrote, citing an alleged message from Robinson: "I had the opportunity to take out Charlie Kirk and I took it."
"There is no mention of any threat or intended harm to any other individual(s)."
Prosecutors have a deadline next week to reply to the brief. Graf's decision is expected at the Sept. 1 hearing.
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Donna Rotunno, a Chicago-based lawyer and Fox News contributor, said Robinson's argument is a long-shot, especially at the probable cause stage of the case.
"The evidence in the preliminary hearing has already proven that there were many people there," she told Fox News Digital Wednesday. "The evidence has shown where the shooter was vs where Charlie was and where the shot was taken from, the amount of people who were in the line of fire. They can argue those facts from other pieces of evidence that they've introduced. They didn’t need somebody specifically to get on the witness stand and say there were all these people in danger."
Prosecutors have alleged that Robinson is the man who appears on surveillance video approaching a sniper's perch. According to investigators, the killer opened fire from a rooftop on the far side of the packed courtyard, which was full of spectators.
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"If you drive a car into a crowd, that whole crowd is in danger," Rotunno added. "I don’t think that argument is a stretch."
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Robinson's lawyers also renewed their attempt to throw out hearsay evidence from the preliminary hearing , arguing that prosecutors haven't established its reliability.
Similar objections failed in July, and Rotunno said she expects them to fail again.
"They're relitigating many issues that the judge has already ruled on, and they're going nowhere," she said.
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The defense is also asking Graf to strike two lesser charges — witness tampering and committing a violent offense in the presence of a child — arguing that Robinson was advising his roommate Lance Twiggs to exercise his constitutional rights and that prosecutors failed to show Robinson knew children were present at the time of the shooting.
And they argue that the enhancement that Kirk was targeted for his political expression should also be dropped, disputing an alleged text from Robinson to Twiggs stating, "I had enough of his hatred."
"It is the State that argues that because Mr. Robinson and Mr. Twiggs are two men who love each other and/or, it speculates, because Mr. Twiggs (and not Mr. Robinson) was at least intermittently identifying as a female to his close friends, it is Mr. Kirk’s views on these topics which are the 'hatred' Mr. Robinson was referring to," the defense wrote. "These circumstances are not sufficient to establish, even by probable cause which if any political expression of Mr. Kirk motivated Mr. Robinson to select Mr. Kirk for an act of violence."
Robinson has not yet entered a plea.
