Charlie Kirk, an influential conservative activist and a close ally of US President Donald Trump, was shot dead while speaking at an event at a university in Utah.

There is still a lot that is unclear about the incident but here is what we do know.

What happened?

Kirk, 31, who had been invited to speak at Utah Valley University (UVU), was seated under a white gazebo addressing a crowd of about 3,000 people in the quad, an outdoor bowl courtyard.

According to eyewitnesses and videos taken at the scene, he was responding to a question about gun violence when a single shot rang out around 12:20 local time.

Kirk can be seen recoiling in his chair, with blood visible on his neck, before the terrified crowd starts running.

“I heard a loud shot, a loud bang and then I saw his body actually – in slow motion – kind of fall over,” one eyewitness told reporters.

“We all dropped to the ground, and I want to say we sat like that for about 30 to 45 seconds, and then everyone around us got up and started running,” said Emma Pitts, a reporter from Deseret News.

Kirk was rushed to hospital in a private vehicle. Hours later, Trump confirmed his death on a post on Truth Social.

The university campus has since been evacuated, as authorities search for the shooter.

Kirk’s wife and two children were at the scene, but are safe. No-one else at the event, or on campus, was injured.

Who is the suspect?

Authorities say this was an assassination – but we don’t know yet who shot Kirk, or why.

Two people were arrested in the hours after the incident and later released. They have “no current ties” to the shooting, Utah officials have said.

“This shooting is still an active investigation,” the Department of Public Safety, which covers law enforcement in the state, said in its latest update.

A massive manhunt is under way for the shooter. The campus has been locked down and heavily-armed police are going door-to-door as part of the search, the BBC’s Regan Morris reports from the campus.

Law enforcement officials say the killer is believed to have fired the fatal shot from the roof of a building that is located near the courtyard where Kirk was speaking.

They say they are going through CCTV footage, and believe the suspect was “dressed in dark clothing”.

BBC Verify has been examining videos posted on social media, which people claim show a figure on the roof of a university building after the attack.

It was posted on X after the shooting, but we cannot verify when it was filmed.

The poor quality of the video makes it hard to determine what the dark shape pictured in it might be. Based on the building’s characteristics, the BBC was able to identify it as UVU’s Losee Center – a campus spokesperson has said the shot came from there.

Credit: BBC