As a prosecutor, Mars, who died Tuesday, would captivate a courtroom, the Chcago Sun-Times said.

He was the lead prosecutor in the Family Secrets mob trial which won convictions of notorious Chicago mobsters including Joey "The Clown" Lombardo. But, when the verdict came in last September, he ran from photographers, the Sun-Times said. His boss had to order him to the news conference.

Defense attorney Rick Halprin, who opposed him in the case, called Mars "brilliant. And a straight shooter. You could take his word for anything."

U.S. District Judge James Zagel told the Sun-Times that Mars had a "tremendous presence" despite his ordinary looks and demeanor. "He just radiated truth every time he spoke."

Two weeks after the Family Secrets trial, he saw a doctor about a persistent cough and was diagnosed with lung cancer although he wasn't a smoker, the newspaper report said.

He was survived by his wife Jennifer.