WASHINGTON

Prosecutors in the US state of Utah said Friday that they will seek the death penalty for Tyler James Robinson, 22, who has been charged with last week's fatal shooting of right-wing commentator Charlie Kirk.

Robinson was charged with aggravated murder, a capital offense, and felony discharge of a firearm causing serious bodily injury. Prosecutors alleged he targeted Kirk for his political views.

Additional charges include obstruction of justice for concealing the rifle and clothing used in the attack, and witness tampering for directing his roommate to delete incriminating messages and remain silent if questioned. He also faces a misdemeanor count for committing a violent offense in the presence of a child.

"The murder of Charlie Kirk is an American tragedy. 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 in a search for truth, understanding and a more perfect union," Utah County Attorney Jeff Gray told reporters at a news conference.

Kirk, 31, was fatally shot on Sept. 10 while addressing a group of students at Utah Valley University in the city of Orem, some 40 miles (64.4 kilometers) south of Salt Lake City.

Gray said DNA "consistent with" Robinson's was found on the trigger of a rifle recovered by investigators near the scene of Kirk's shooting, as well as on other parts of the rifle, the towel it was wrapped in, the casing of a fired piece of ammunition, and three other unfired cartridges.

Robinson was taken into custody last Thursday in Washington County after relatives alerted law enforcement. A bolt-action rifle and bullet casings with engravings were recovered near the campus of Utah Valley University, where the deadly shooting took place, officials said. He remains in custody in Utah County Jail.

While the motive remains unclear, Gray said investigators recovered text messages in which Robinson allegedly admitted to the shooting to his roommate, who he described as a romantic partner and a "biological male who was transitioning genders."

"I had enough of his hatred. Some hate can't be negotiated out," Robinson allegedly wrote to his roommate.

Gray said that a search of Robinson's residence uncovered a note in which he allegedly said, "I had the opportunity to take out Charlie Kirk, and I'm going to take it."

Robinson later made his first court appearance via video link, with Judge Tony Graf reading the charges against him, along with the prosecutors’ arguments behind them.

He also granted a pretrial protective order for Erika Kirk, Kirk's widow, and said the next hearing, a waiver proceeding, was scheduled for Sept. 29, with Robinson remaining in custody without bail.

*Michael Hernandez contributed to this report from Washington