Among the perks of doing it at HBO, they say, was the ability to explore the sci-fi genre in the way other series on the network have done thecop and mob genres.
Mr Caracappa was a former member of the New York Police Department's organised crime homicide unit, while Mr Eppolito - son of Gambino footsoldier Ralph "Fat the Gangster" - co-authored the 1992 book Mafia Cop: The Story of an Honest Cop Whose Family Was theMob.