Charlie Kirk, a right-wing activist and a key ally of Donald Trump, was shot and killed on Wednesday at an event at Utah Valley University in Orem, Utah.

Governor Spencer Cox called the shooting a “political assassination.”

Six hours after the shooting, authorities have yet to identify the suspect. Federal Bureau of Investigation (FBI) Director Kash Patel said the suspect in Kirk’s shooting was taken into custody and released after questioning. It was not immediately clear who he was or what his motive was.

Governor Cox said at a news conference that police were questioning a “person of interest,” but did not provide further details. Utah Department of Public Safety Director Beau Mason added that the shot that killed 31-year-old Kirk was fired by a “suspect who is still at large.”

In a video message posted on his Truth Social platform, Donald Trump said: “My administration will identify all those involved in this crime and political violence in general, including the organizations that fund and support it.”

By order of Trump, the national flag in the United States was lowered to half-mast in memory of the murdered Charlie Kirk.

The moment of the shooting was recorded on mobile phones. The videos show how Kirk is speaking in front of a large audience when the shot rings out at 12:20 local time. He reaches for his neck and falls from his chair.

A video is circulating online, showing the alleged killer on the roof of the university.