New video shows Trump shooter climbing onto the roof at rally | ABC News |

Heavily armed local police were stationed inside the building and missed Thomas Crooks climbing outside to the roof.

Witnesses said they frantically tried to warn Secret Service agents about a suspicious man on the roof of the manufacturing plant moments before he unleashed his deadly onslaught.

"He was up there for a couple of minutes, absolutely at least three, four minutes. We were pointing at him for the Secret Service, who were looking at us from the top of the barn. They were looking at us the whole time," Greg Smith told the BBC.