Utah governor says the motive in Kirk shooting is not yet certain but the suspect was on the left

Cox said Robinson, 22, is “not cooperating” and that friends paint a picture of someone radicalized in the dark corners of the internet. “Clearly there was a lot of gaming going on,” Cox said on NBC. “Friends have confirmed that there was kind of that deep, dark internet, the Reddit culture, and these other dark places of the internet where this person was going deep.”

A Republican who's called on all partisans to tone down their rhetoric following the attack, the governor added: “I really don’t have a dog in this fight. If this was a radicalized MAGA person, I’d be saying that as well.”

Cox stressed on several Sunday morning news shows, however, that investigators are still trying to pin down a motive for the attack on the father of two and Trump confidant, who was killed Wednesday while on one of his signature college speaking tours at Utah Valley University. The governor said more information may come out once the suspect, Tyler Robinson, appears in court Tuesday.

The governor said the suspect's partner was transgender, which some politicians have pointed to as a sign Robinson was targeting Kirk for his anti-trans views. But authorities have not said whether it is relevant as they investigate Robinson’s motive.

“The roommate was a romantic partner, a male transitioning to female,” Cox said. “I can say that he has been incredibly cooperative, this partner has been very cooperative, had no idea that this was happening.”

Investigators have spoken to Robinson’s relatives and carried out a search warrant at his family’s home in Washington, about 240 miles (390 kilometers) southwest of Utah Valley University, where the shooting took place.

State records show Robinson is registered to vote but not affiliated with a political party and is listed as inactive, meaning he did not vote in the two most recent general elections. His parents are registered Republicans.

Ammunition found with the weapon used to kill Kirk was engraved with taunting, anti-fascist and meme-culture messages. Court records show that one bullet casing had the message, “Hey, fascist! Catch!”

Robinson grew up around St. George, in the southwestern corner of Utah between Las Vegas and natural landmarks including Bryce Canyon and Zion National Parks.

Robinson became a member of The Church of Jesus Christ of Latter-day Saints, known widely as the Mormon church, at a young age, church spokesperson Doug Andersen said.

Robinson has two younger brothers, and his parents have been married for about 25 years, according to social media posts. Online activity by Robinson’s mother reflects an active family that took vacations to Disneyland, Hawaii, the Caribbean and Alaska.

Like many in that part of Utah, they frequently spent time outdoors — boating, fishing, riding ATVs, zip-lining and target shooting. A 2017 post shows the family visiting a military facility and posing with assault rifles. A young Robinson is seen smiling as he grips the handles of a .50-caliber heavy machine gun.

A high school honor roll student who scored in the 99th percentile nationally on standardized tests, he was admitted to Utah State University in 2021 on a prestigious academic scholarship, according to a video of him reading his acceptance letter that was posted to a family member’s social media account.

But he attended for only one semester, according to the university. He is currently enrolled as a third-year student in the electrical apprenticeship program at Dixie Technical College in St. George.

Riccardi reported from Denver.