How is that possible? Were they already monitoring that particular rooftop?

My understanding is the range from the shooter to the stage is more like 150 yards, not 300 yards. At least one Secret Service sniper was on a rooftop a bit closer to the shooter, and appears to have been looking in the direction of the shooter at the time of the shooting.

There’s also a report that a citizen was trying to raise an alarm over a suspicious person on a rooftop with a gun. Whether that was successful or was the actual shooter is something that will have to be determined in the investigation.

I’m not surprised that they were able to locate and neutralize the shooter quickly. That is exactly their job and what they are trained to do. If they did indeed have a tip that something was up, that could have sped up their response.

—Peter