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Crimefighters who took on the Mob

A number of law enforcement officers and other public and private investigators have earned public notice for their work against organized crime. Some sacrificed their lives in that work. Items within the table of contents below link to brief biographies of individuals who became famous for tangling with the Mob. Click the headlines or photos to read the full bios.

Det. Arthur Carey

Carey, Arthur

New York Police Department

Carey served for nearly four decades on the NYPD and spent eighteen years as head of the Homicide Bureau. Brought into the force in 1889, under Chief Inspector Thomas Byrnes and Captain "Chesty" George McClusky, he became an old-school deteective in 1892. He helped investigate the infamous Barrel Murder, the murder of "Joe Pep" Viserti and the murder of Arnold Rothstein. His memoirs were published in 1930.

Charles Cavolo

Cavolo, Charles

Cleveland Police Department

After emigrating from Italy as a teenager, Cavolo grew up along Cleveland's Mayfield Road with many who became the city's most notorious gangsters. On Cleveland's police force, he became successful in investigations of organized crime and gangland murders. He was a member of the city Black Hand Squad and later leader of the automobile bureau, where he uncovered an interstate tire theft ring.

Operative Francis Dimaio

Dimaio, Francis

Pinkerton Detective Agency

His career with the Pinkerton Agency included pursuing Butch Cassidy in South America. Dimaio engaged in a number of dangerous undercover operations against the U.S. Mafia. He went into Orleans Parish Prison as a prisoner to unravel the 1890 assassination of police Chief David Hennessy. He also helped break up Mafia counterfeiting, extortion and kidnapping rings in western Pennsylvania and the Midwest.

Michael Fiaschetti

Fiaschetti, Michael

New York Police Department

An Italian immigrant, Fiaschetti was a pupil of Lieutenant Joseph Petrosino on the famed NYPD Italian Squad. He was large and powerful and unashamedly old school in his tactics. In the early 1920s, he briefly led a resurrected Italian Squad and traveled to Italy to learn about the murder of his mentor. After retirement, he ran his own detective agency and traveled lecturing on police subjects.

Chief David Hennessy

Hennessy, David

New Orleans Police Department


After trying in vain to resolve a conflict between local Mafia factions, Chief Hennessy chose to discover what he could of the Mafiosi's Old Word criminal records from Italian officials and have the gangsters deported. The decision resulted in his 1890 assassination, less than a block from the home he shared with his widowed mother.

Eliot Ness

Ness, Eliot

U.S. Treasury Department

Portrayed inaccurately in television, radio and movie accounts, Ness was leader of the U.S. Treasury Department's "Special Prohibition Unit" in 1920s Chicago. Ness later moved into city policing, becoming director of public safety in Cleveland in the late 1930s and modernizing that police department. He left public service in the 1940s and died just as his memoirs, The Untouchables, was published.

John Frank Oldfield

Oldfield, John Frank

United States Postal Inspection

Perhaps the most renowned member of the U.S. Postal Inspection Service (the most important federal law enforcement agency of his era), Oldfield was able to unearth an interstate ring of Mafia Black Hand extortionists, known as the Society of the Banana and based in Ohio. His investigation found common threads in the assassinations of New Orleans Chief Hennessy and NYPD Lieutenant Petrosino.

Lieutenant Joseph Petrosino

Petrosino, Joseph

New York Police Department


A highly regarded opponent of organized crime in New York City, Lieutenant Petrosino was sent across the Atlantic in 1909 to battle the Camorra and Mafia on their home turf. While gathering information on Mafiosi who left Sicily for the U.S., Petrosino was murdered in Palermo. He became the first NYPD officer to lose his life while on duty overseas.