From last June, a possible similar situation was reportedly stopped in California when the planned shooter called the local police himself and turned himself in saying something about the CIA and he did not want to be a patsy and die. this happened about six days after the Orlando nightclub shooting.
The California incident occurred the same day/or nearly the same day a young British man tried to take an officer’s weapon to shoot Mr. Trump at a rally.
I think we are on to something. Air Canada is now saying Santiago was NOT ON THE FLIGHT, and they never checked in a gun.