[anymouse]

Something so obvious that it hasn't been noticed by anyone else yet. Given the fast pace and accuracy of this assassin, it is unlikely that he is using a series of homemade supressors. Thus it is likely that he is using a military grade sniper weapon with attachable sniper-grade silencer. Probably a scope too, maybe with laser target painter.

Likely he is firing from the cover of a non-descript vehicle, that he can quietly drive away without drawing much attention to himself (maybe a truck or van that he can go from the back to the driver seat without going outside.) Or he has a accomplice that drives him away as soon as he gets a shot off.

[Yasotay]

Thus it is likely that he is using a military grade sniper weapon with attachable sniper-grade silencer. Probably a scope too, maybe with laser target painter.

I have fired the M-21 (with suppressor) and the M-24. Most .223 rounds cannot be silenced (unless you get special subsonic rounds). There were "reports" according to the reports, I doubt if he is using a suppressor. He/They clearly can shoot ... as far as I can tell it still could be any weapon.