In 1964, Richard Kuklinski dates Deborah Pellicotti and kills a man who made an offensive comment about her during a game of pool. The violent Kuklinski works dubbing porn films but he tells Deborah that he dubs Disney cartoons. Soon they get married and have two daughters. When his boss Roy Demeo closes the laboratory where Kuklinski works, he is invited to work as contract hit man after a test killing a homeless man. Over the years he works for Roy but he falls in disgrace when he lets a teenage hooker who witnessed a killing go free because he doesn't kill children. Kuklinski begins to work independently as a freelancer, irritating Roy, who threatens him and his family. In 1986, Kuklinski is arrested by the police after committing more than 100 murders.
—Claudio Carvalho, Rio de Janeiro, Brazil