William L. Murphy

Murphy was elected president of the National Association of District Attorneys in 1998.

He advocated for strict environmental regulations and legislation after prosecuting John Cassiliano, a sanitation supervisor at the Brookfield landfill who took bribes in exchange for allowing illegal dumping of toxic waste, in 1982. In 1988, he prosecuted Andre Rand, who was convicted of kidnapping and murdering a 12-year-old girl with Down Syndrome. In 2003, he prosecuted Ronnell Wilson, who was convicted and served the death penalty for murdering two undercover detectives. Murphy retired shortly afterward. While serving as District Attorney, Murphy suffered from diabetes and needed a new kidney. Two staff members in the Richmond County District Attorney's office donated a kidney to Murphy but both kidney transplants were not successful.

Murphy was a public prosecutor in the New York County District Attorney's office from 1969 to 1975. From 1975 to 1982, he was the chief assistant district attorney in Staten Island. In November 1982, he became acting district attorney when Thomas R. Sullivan resigned to become a judge. He was appointed as district attorney by Governor Mario Cuomo in March 1983 and then continued in the position for 20 years, through five elections. New York City Mayor Michael Bloomberg called him a "legendary public servant" upon his death.

William Leo Murphy (June 25, 1944 – June 4, 2010) was the Richmond County District Attorney (in Staten Island, New York) from 1983 to 2003.