This is the witness who saw the attacker on the roof before shooting Trump

A witness case told police he saw the attacker switching from one roof to another shortly before he shot former US President Donald Trump at Saturday's rally in Pennsylvania.

Ben Macer was along the fence line when he saw “moving from one roof to another. (I) told an officer that the killer was on roof”.

When I came back to where I was, it was the time when and then it started shooting, and then it was just chaos, and we all came out running away, and that's it” Macer told the KDK.

Authorities have identified 20-year-old attacker, Thomas Matthew Criux, who was killed by Secret Service agents at the scene.

The FBI in a statement issued early this morning said the 20-year-old was a resident at Betherel Park in Pennsylvania, 35 miles from where Trum held the rally yesterday.