The "absence of evidence is not evidence" some contrarian philosopher once said. We know someone was on the 6th floor. Witnesses saw a rifle pointed out the window. We know that person got off that floor without being noticed.
On the contrary, Mr Smith--------------he was noticed, by Officer Baker, who caught him "walking away from the stairway" a number of floors up the building

And, a little after this, he was noticed running out of the building

This latter sighting was the true source of the suspect description that went out
