The Officer who Confronted Thomas Matthew Crooks on the Roof

The officer who confronted Thomas Matthew Crooks on the roof radioed a "blanket tactical channel" that there was "an individual on the roof with a weapon" before the assassination attempt on President Trump.

Why wasn't President Trump immediately evacuated?

Was the Secret Service listening to this "blanket tactical channel"?

Two officers went to the lowest point of the building. One officer boosted the other high enough to reach the roof, where he saw the shooter with a weapon.

Crooks turned and pointed his weapon at the officer, who then ducked and fell off the roof.

"The boosting officer and the officer that fell were both on the radio indicating that there was an individual on the roof that did, in fact, have a weapon."

"There was a blanket tactical channel being used. Everyone who was on that tactical channel heard it."

How much time was there between that radio communication and the gun being fired at President Trump?

It's bad enough that the Secret Service didn't put anyone on the most obvious roof 150 yards away.

But after two police officers radioed in that there was a guy on the roof with a gun, why wasn't President Trump immediately evacuated?