OREM, Utah (AP) A 22-year-old Utah man who was arrested and booked on murder charges in the assassination of Charlie Kirk held deep disdain for the conservative activist’s provocative viewpoints and indicated to a family member that he was responsible for the shooting, authorities said Friday.

The arrest marked a major break in a case that shocked the country and raised fresh alarms about political violence in a deeply polarized United States.

Tyler Robinson, 22, had become “more political” in the run-up to the shooting and mentioned during a dinner with family that Kirk would be visiting Utah, Gov. Spencer Cox said at a news conference. The governor cited as evidence engravings on bullet casings found in the rifle that authorities believe was used in the attack, as well as chat app messages attributed to the suspect that a roommate shared with law enforcement.

The governor credited Robinson’s family with helping turn him over to authorities.

“Ladies and gentlemen, we got him,” Cox said soon after the arrest was first heralded by President Donald Trump on the Fox News show “Fox & Friends.”

Robinson is believed to have acted alone, and the investigation is ongoing, Cox said. He was arrested on suspicion of capital murder, weapons and obstruction offenses. He was expected to be formally charged Tuesday ahead of an initial court appearance.

Robinson’s arrest late Thursday capped a frenetic day-and-a-half search that just hours earlier seemed stuck when authorities pleaded for tips and leads from the public. The assassination captivated the public not only because of Kirk’s outsize influence in conservative political circles and his close connections with Trump but also because of the pressing questions it raised about the escalating toll of political violence that has spanned the ideological spectrum.

“This is our moment: Do we escalate or do we find an off-ramp?” Cox asked, making an impassioned plea for young people to bridge differences through common ground rather than violence. “It’s a choice.”

New details on evidence

Authorities have yet to reveal a motive, but they did describe evidence they said shed potential light on the slaying.

That includes engravings on bullet casings recovered from the high-powered rifle believed used in the attack, including one that said, “Hey, fascist! Catch!” Cox said.

In addition, a roommate shared with authorities messages from the chatting app Discord that involved a contact named Tyler and discussed a rifle wrapped in a towel, engraved bullets and a scope, the governor said. A Mauser .30-caliber, bolt-action rifle was found in a towel in a wooded area along the path investigators believe Robinson took after firing a shot from a distant roof and then fleeing.

The clothes the suspect wore when confronted by law enforcement late Thursday were consistent with what he had on when he arrived on campus a day earlier, and a family member confirmed that he drove a gray Dodge Challenger like the one seen in surveillance video that recorded Robinson driving to the university on the day of the shooting, Cox said.

Robinson’s father recognized him from the photos released by the FBI and told him to turn himself in. Robinson refused at first, but then changed his mind, according to a law enforcement official who spoke on the condition of anonymity to discuss an ongoing investigation. His father reached out for help to their youth pastor, who also occasionally works with the U.S. Marshals and called the agency so he could turn himself in.

Meanwhile, investigators continued to dig into the background of Robinson, who was admitted to Utah State University, about 80 miles north of Salt Lake City, on a prestigious academic scholarship, according to a video of him reading his acceptance letter posted to a family member’s social media account. However, he attended for only one semester in 2021, a university spokesperson said.

Robinson’s address was still listed as his parent’s home, and he is registered as an unaffiliated voter, according to Utah state records. He does not appear to have a prior criminal record. The family lives in a suburb of the city of St. George in southern Utah, about a 3.5-hour drive south of the Utah Valley University campus where Kirk was shot.

Family members of Robinson did not immediately return messages seeking comment. It was not clear if he had a lawyer.

At his family’s home, window coverings were drawn, and a pickup truck blocked access to the driveway. There was a heavy law enforcement presence, with several police vehicles parked along the street, which was closed at both ends.

‘He didn’t deserve this’

Kirk was a conservative provocateur who became a powerful political force by rallying young Republican voters and was a fixture on college campuses, where he invited sometimes-vehement debate on social issues.

Kirk co-founded the nonprofit political organization Turning Point USA, based in Arizona. He had had been speaking at a campus debate on the first stop of his “American Comeback Tour,” at the time of Wednesday’s shooting.

He was taking questions from an audience member about gun violence when a shot rang out. Kirk reached up with his right hand as blood gushed from the left side of his neck.

Trump, who was joined by Democrats in condemning the violence, said he would award Kirk the Presidential Medal of Freedom, the highest civilian honor in the U.S. Vice President JD Vance and his wife, Usha, visited with Kirk’s family Thursday in Salt Lake City and then escorted Kirk’s casket to his home state of Arizona aboard Air Force Two.

“He wanted to help young people, and he didn’t deserve this,” Trump said Friday. “He was really a good person.”