Volz died Saturday in a Tulsa, Okla., hospital after a long illness, said his widow, Daisy Volz. He had been a federal administrative law judge there for the past six years until he retired Dec. 31, she said.
Volz was the chief federal prosecutor for the Eastern Judicial District of Louisiana from 1978 until 1990. He tried Edwards twice on racketeering charges in the 1980s stemming from an alleged health care scheme, but one trial ended in a hung jury and the second resulting in acquittal.
Edwards, who served an unprecendented four terms as Louisiana governor, was recently released from federal prison on a 10-year sentence for extorting casino license applicants during the 1990s.
Volz convicted Marcello in a bribery case with national implications known as Brilab, although that verdict was overturned in 1989.
U.S. District Judge Lance Africk of New Orleans, who worked as Volz's chief of criminal prosecutions from 1982 to 1990, called his former boss "a honorable person" with nothing but the public's interest in mind. Edwards often accused Volz of persecution without evidence.
"The only trail he followed was the trail of evidence," Africk said. "He was fearless when it came to public corruption cases."
Volz, who was appointed by President Jimmy Carter and served through Ronald Reagan's administration, left in 1990 after President George H.W. Bush replaced him with Harry Rosenberg. Volz then served as a special counsel to the U.S. attorney general.
In the 1990s, Volz ran unsuccessful campaigns for St. Tammany Parish sheriff and for a two-parish district attorney's post.
Funeral arrangements were pending. Daisy Volz said her husband would be returned to his native New Orleans.