Islam loves assassinations as a tool of intimidation and war. Mohamed ordered three of them
This might have been a flyin-flyout the same day hit which is very hard to track. The mafia liked those hits, no local morons to yap, brag and sequel.
Also the LEOs and prosecutors know their families could be killed the same way.
I'm betting that it wasn't. It was a muslim ritual beheading, for anti-muslim blasphemy.
That said, islam (note the small "i", a sign of my disrespect) is not a religion, in any sense of the word. Rather, it is a political system of total control over every aspect of its mindless, robotic adherents' lives. islam encourages and breeds hatred, terrorism and murder. I know of no other modern religion which does that. islam is all about women-chattelling, boy-buggering, ritual killing, beheading, infidel-killing, rape, lying, female mutilation, martyrdom, poverty and complete submission or death.