New details have emerged about Tyler Robinson, the 22-year-old accused of assassinating conservative activist Charlie Kirk. According to reports, Robinson was living with a transgender partner who is now cooperating fully with federal investigators.

The partner, who is said to be transitioning from male to female, provided authorities with key text messages and communications that helped track down Robinson. Neighbours confirmed the pair shared a condo featuring amenities such as a pool, hot tub, and walking trails, located about five miles from Robinson’s family home.

Sources told the New York Post that the partner’s information was critical, revealing details about bullet casings inscribed with meme-style messages similar to those found at the crime scene, as well as conversations about retrieving a rifle from a drop point.

Kirk, 31, co-founder of Turning Point USA and a prominent Trump ally, was fatally shot in the neck on Wednesday while speaking at Utah Valley University. His final exchange came in response to a student’s question about transgender mass shooters. He was rushed to hospital but later died of his injuries.

The attack has been widely condemned as a “political assassination.” Utah Governor Spencer Cox called the killing “a dark chapter” and said investigators believe Robinson was “deeply indoctrinated with leftist ideology.”

Robinson, who grew up in a conservative Mormon household, was arrested near his family’s home in southern Utah on Thursday, September 11. He is being held without bail at Utah County Jail and is expected to face charges including aggravated murder and firearms offences.

Friends described Robinson as quiet, geeky, and heavily involved in online communities like Reddit and Discord. His family told investigators that he had become increasingly political in recent years. Authorities say messages allegedly written on the bullets referenced both anti-fascist causes and alt-right meme culture, suggesting a complex ideological motive.

Police confirmed that Robinson’s father assisted with the investigation. Neighbours said Robinson had appeared more withdrawn in recent months.

Kirk is survived by his wife, Erika, and their two young children. His death comes amid a surge in politically motivated violence in the U.S., following last year’s attempted assassination of former President Trump and the killing of Minnesota state representative Melissa Hortman.

A Trump advisor broke down live on Fox News upon learning of Kirk’s death, saying he believed Kirk “would have been president one day.”