Here. I found some examples.
Florence Kenyon (1910s-1920s, New York City) – Campaigned on going after mobsters and organized crime figures like Lucky Luciano.
Thomas Dewey (1942, New York City) – Ran focusing on prosecuting Mafia boss Frank Costello and “cleaning up Times Square.” Later became Governor of New York.
Thomas Eagleton (1951-1953, St. Louis, MO) – Ran focusing on prosecuting mob boss Anthony “Tony G” Giordano and organized crime figures.
Robert Morgenthau (1974-2009, Manhattan, NY) – Campaigned on going after high-profile figures like John Gotti, Philip Agnello, and other mob leaders as part of the “Italian Squad” unit.
Tom Steffen (1981-1987, Hennepin County, MN) – Promised to pursue cases against “teamsters bosses” like Jackie Presser during his election.
Jim Garrison (1962-1973, Orleans Parish, LA) – Gained attention for investigating New Orleans businessman Clay Shaw in relation to the assassination of President John F. Kennedy.