He's Fair Game Even If He Is A Cop!

Above: In my opinion the greatest Godfather scene of all time

When his father is nearly assassinated in 1945, he volunteers to murder the man responsible, Virgil "The Turk" Sollozzo (Al Lettieri). He also proposes to kill Captain McCluskey (Sterling Hayden), a police captain who removed his father's bodyguards from the hospital, presumably to set up his father to be killed. Although it is normally a hard-and-fast rule in the Mafia that law enforcement officials are not to be harmed, Michael successfully convinces his elder brother Sonny (James Caan) that since McCluskey is serving as Sollozzo's bodyguard, he has crossed into their world and is fair game.

After committing the murders, Michael flees to Sicily under the protection of Don Tommasino, a longtime friend of his father's, and stays in exile for two years