Captain McCluskey was a corrupt police captain portrayed by Sterling Hayden.
Mark McCluskey's father was also a police captain who took his son on visits around the district, where he would be given gifts of cash by the shopkeepers, who were under his father's protection. It was then that his son decided to follow in his father's footsteps. At first McCluskey was an honest and tough cop, but he became easily susceptible to bribes. He was also good friends with Bruno Tattaglia, who had gone to Fordham with one of McCluskey's four sons. McCluskey would clear the records of Bruno's employees in return for large cash rewards, and free trips to Bruno's Midtown restaraunt, The Luna Bar.This friendship led to McCluskey meeting Virgil Sollozzo, and eventually becoming his hired bodyguard, the money paying for the funeral of his sister-in-law back in Ireland. McCluskey assited Sollozzo by removing the guard on Vito Corleone's hospital room, so that Solozzo and his men would have a clear shot on the wounded Don.However, the Don's son Michael happened to visit that evening and noticed the lack of guards. Michael called his brother Sonny about the problem and moved Vito to a different hospital room. Once outside, he managed to scare off Sollozzo and his men with the help of Enzo Aguello, which caused the Turk to call McCluskey and remove the two men. Michael questioned McCluskey as to how much he was being paid by Sollozzo, which resulted in the police captain breaking Michael's jaw. Before he could harm him further, the Corleone Family consigliere Tom Hagen arrived with men licensed to carry firearms in order to protect the Don. McCluskey backed down and disppapeared into the night. In order to get rid of Sollozzo, Michael called a meeting between them, with McCluskey attending. Michael excused his himself and visited the lavatory to receive a planted gun. He returned and dispatched McCluskey with two shots. After this shooting, the police came down hard on the Five Families, which hit the Corleones particularly hard, as most of their business was in the open. However, after Tom Hagen planted stories in the media linking McCluskey to Sollozzo, the police's search for blood subsided.