Ok, so without a doubt, attempted murder, first degree.

You WILL find a lot of these young idiots being smart enough to know that if real street warfare breaking out, that they are not going to want any part of it; especially if a few dozen/hundred start getting picked up as "accessories", which they are if shooting starts and they are still trying to stop the victim from escaping.

On the other hand, if the mob starts to do this, they will start getting gunned down by armed citizens.

Be aware, an ar15 is not the best weapon against multiple attackers if they are committed to pressing on an attack, unless you are really proficient with it.

Trust me an Eotech or other holographic red dot sight is amazing for hitting targets in a second or less, if trained and in practice.