After a Senate briefing from the Secret Service regarding the attempted assassination of Donald Trump, Sen. John Barrasso (R-WY) told Fox News that the Secret Service had identified the shooter, Thomas Crooks, "as a character of suspicion" over an hour before the shooting occurred:

“He was identified as a as a character of suspicion because of saw [sic] a rangefinder as well as a backpack. And this was over an hour before the shooting actually occurred. So, you would think over the course of that hour, you shouldn't lose sight of the individual. Somebody ought to be following up on those sorts of things. No evidence of that happening at all.”

Fox's Aisha Hasnie also reported that:

In addition, the report states that "the Secret Service agent in charge of security at the event was on the phone with local and state police about the threat while the shooting took place."

There is absolutely no excuse for the Secret Service allowing Trump to take the stage while this character of suspicion was at large, with an identified threat, and with civilians standing near the building on which Crook was perched screaming to law enforcement that there was a man with a gun up there.