Editing Black Hand (extortion) (section)

==Law enforcement and decline==
Municipal Italian squads, postal inspectors, federal agents and local prosecutors investigated Black Hand letters, bombs and interstate schemes. New York's Italian Squad was led by Joseph Petrosino, while other cities developed Italian-speaking police and community responses.<ref>Nelli, ''Business of Crime'', pp. 79–100.</ref> Convictions were difficult because victims feared retaliation and “Black Hand” did not identify one membership organization. Reliance on mailed threats nevertheless created federal jurisdiction; mail prosecutions and severe sentences increased the risks of interstate schemes.<ref name="Critchley" />

The practice and label declined unevenly after approximately 1915 and largely faded during the 1920s rather than ending with the dissolution of one body. Contributing factors included federal enforcement, explosives controls, prosecution of particular crews, greater victim cooperation and changes in tightly bounded immigrant neighborhoods. Prohibition changed criminal opportunities, but the newer Mafia was not simply a renamed Black Hand Society and most Black Handers did not graduate into organized bootlegging.<ref name="Lombardo" /><ref>[https://books.google.com/books?id=2eCPAgAAQBAJ&pg=PA34 Critchley, ''Origin of Organized Crime'', pp. 34–35].</ref>