Roy Marcus Cohn was an American lawyer who came to prominence for his role as Senator Joseph McCarthy's chief counsel during the Army–McCarthy hearings in 1954, when he assisted McCarthy's investigations of suspected communists. Modern historians view his approach during those hearings as dependent on demagogic, reckless and unsubstantiated accusations against political opponents. In the late 1970s and during the 1980s, he became a prominent political fixer in New York City. He represented and mentored the real estate developer and later US President Donald Trump during his early business career.
Born in The Bronx in New York City and educated at Columbia University, Cohn rose to prominence as a U.S. Department of Justice prosecutor at the espionage trial of Julius and Ethel Rosenberg, where he successfully prosecuted the Rosenbergs leading to their execution in 1953. As a prosecuting chief counsel during the trials, his reputation collapsed during the late 1950s to late 1970s after McCarthy’s downfall.