Devil's Advocate, we want them to clearly identify the target and what may be behind the target.
Still seems a bit slow and sloppy, ngl.
We also don't know how long the assassin was exposed carrying a rifle and taking a position before opening fire
Discussion
Either the secret service is retarded. Or it was an inside job.
That building roof should have been secured. There were very few places for a sniper perch, and that was so close and so obvious.