Charlie Kirk, an influential conservative activist and close ally of US President Donald Trump, was shot dead while speaking at an event at a university in Utah.
There's still a lot that is unclear about the incident but here is what we do know.
Kirk, 31, had been invited to Utah Valley University (UVU) and 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, blood on his neck, before the terrified crowd starts running.
