One sniper inside spotted the gunman, Thomas Matthew Crooks, outside and looking up at the roof, observing the building and disappearing, according to the officer who spoke to CBS News. The sniper observed Crooks as he returned to the building, sat down and looked at his phone. At that point, one of the local snipers took a picture of Crooks.
Next, the local sniper observed Crooks looking through a rangefinder, an instrument routinely used by marksmen to determine the distance of a target, and he immediately radioed to the command post, according to the local law enforcement officer. The local sniper also attempted to send the photo of the gunman up the chain of command.
Officials then lost track of Crooks, who disappeared, but soon returned for a third time with a backpack. The local sniper team called for backup — alerting the command post that the gunman had a backpack and was walking toward the back of the building.
Two other municipal police officers who heard the call for back-up attempted to climb onto the roof. Butler County Sheriff Michael Sloupe told CBS Pittsburgh station KDKA that an armed municipal officer with Butler Township was hoisted by another officer onto the roof of the building where the gunman had taken a position. Crooks focused his rifle towards the officer who ultimately let go, falling off the roof. Moments later, the shooter began firing into the crowd.
In a reasonable world, Crooks wouldn’t have even been allowed to go near the building. In a less reasonable world, Crooks would have been confronted by armed men as soon as they saw him look through a rangefinder. In a world that was the least bit reasonable, Crooks would have been shot the moment he took a gun out of his bag. But here we are.