Rudolph William Louis “Rudy” Giuliani (born May 28, 1944) is an American lawyer, businessman, former politician, and public speaker from New York. Politically a Democrat, then an Independent in the 1970s, and a Republican since the 1980s, Giuliani was the United States Attorney for the Southern District of New York during the 1980s. Giuliani prosecuted pivotal cases against the American Mafia, and against corrupt corporate financiers.
During his first term as mayor of New York City, Giuliani hired a new police commissioner, William Bratton, who applied the broken windows theory of urban decay, which holds that minor disorders and violations create a permissive atmosphere that leads to further and more serious crimes that can threaten the safety of a city. Within several years, Giuliani was widely credited for major improvements in the city’s quality of life, and in lowering the rate of violent crimes.