Trump attack: Police spotted Thomas Matthew Crooks an hour and a half before the shooting

Law enforcement knew Thomas Matthew Crooks was on the security perimeter with suspicious intentions at least 90 minutes before he fired at Donald Trump. That's what messages between members of the security deployment for the Butler, Pennsylvania rally indicate, unveiled Sunday by The New York Times. 

The messages unveiled by the media outlet show how a local law enforcement sniper warns his colleagues of Crooks' presence in the vicinity of the AGR International building, from where he would fire an hour and a half later. 

The police officer wrote to his fellow officers via messenger after his shift ended around 4:26 p.m., "Someone followed our lead and snuck in and parked by our cars just so you know," the sniper wrote to his fellow officers. "I'm letting you know because you see me go out with my rifle and put it in my car so he knows you guys are up there he's sitting to the direct right on a picnic table about 50 yards from the exit." 

By 17:10, the young man was already right under the snipers positioned on the roof of a warehouse owned by AGR International. One of the snipers photographed him and shared the image with the other team.  "Kid learning around building we are in. AGR I believe it is. I did see him with a range finder looking towards stage. FYI. If you wanna notify SS snipers to look out. I lost sight of him."

After this, Thomas Crooks fired at the stage with his AR-15-type rifle at around 18:10. His gunfire injured several people, including former President Donald Trump, and killed a 50-year-old father and firefighter.