I think the sophistication, intimate logistics, and "tools" used in Colombo's killing. In full view of the entire world no less, strongly points to a more "sophisticated" type "operation" so to speak.

One that smells of FBI, CIA, Black Bag type plannings. The instantaneous killing of the perpetrator, the vanishing of his accomplice. The gun, camera, press credentials, lack of immediate NYPD response to the scene. Like a "Puff" of smoke it all disappears..... a Houdini Act.

IMO, definitely government backed.