This is not even comparable to the assassination attempt on Trump, where the guy fired multiple shots and missed. The person who killed Charlie knew what they were doing, aiming at the jugular artery, possibly a professional. The fact that they couldn't even find the person makes no sense. How long is it going to take for someone to escape the roof top and get away with it? Isn't US intelligence so good it can catch people doing crimes from different parts of country and even the world? If they don't catch the person it's because it WAS an inside job..
I know nothing of these things, but his shirt moved in a way that seemed weird in the first 1-2 video frames of impact.
https://youtu.be/I8jXisOSOns