|Title||Mafia associate, presumably fairly high ranking|
|Appearances||"A Death in the Family"|
|Portrayed by||Robert Costanzo|
When investigating the murder of Doctor Joshua Leeds for his role in a witness protection program, Castle decided to talk with Tenor, reasoning that the mob would already know who Leeds had performed plastic surgery on, and the search could provide them with vital information. Although Tenor initially ordered Castle taken out back, he laughed it off with reassurances that he was just kidding. Talking with Castle, Tenor revealed that Leeds had been murdered to find information on the location of Jimmy 'The Rat' Moran, a former hitman for the Spolano crime family who was forced out of the family when the previous head died and his son took over, Moran turning State's Evidence to avenge himself on the family.
When the Spolanos discovered Moran's location because he was brought out of hiding to talk with Castle and Beckett, Castle briefly wondered if Tenor had tipped them off, but Beckett rejected that possibility as Tenor's associates in a rival family would benefit from the Spolanos being taken out of the picture. ("A Death in the Family")