In 1974, Mr. Sheahen opened his own office in Century City for the practice of criminal law and he began an extraordinary run of victories in homicide cases, most notably the Calhoun, Choi and Kefurt cases from the late 1970s. The Kefurt case was an astonishing achievement -- a complete dismissal of all charges for a young man who had faced the death penalty for the double murder of his mother and father.

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Throughout the 1980s and 1990s, Mr. Sheahen successfully represented hundreds of defendants and he established himself at the highest tier of criminal trial lawyers in Los Angeles. In 1982, he defended the woman accused of the murder of John Belushi. In 1984, he won a hung jury for a Korean murder defendant in a 92-day jury trial in Norwalk. In 1987, he managed to get all charges dropped in the arson case of the man accused of burning down the Los Angeles county library.

In 1991, Mr. Sheahen represented R&B icon Rick James -- accused of torturing a young woman with a crack pipe. In 1996, he won a dismissal of murder charges for a Korean missionary accused of the torture murder of his wife in the now-famous "exorcism" case in Malibu.

He has represented many members of the Hells Angels motorcycle club, including its long-time president George Christie. In 2003, Mr. Sheahen successfully defended a transgendered sex worker, accused in Ventura of murder for the purpose of robbery.

A seminal victory came in 2012 for Lois Goodman.  In a case of international scope, a professional tennis referee was arrested at the United States Open in New York and charged with the murder of her husband.  Three months later, through Mr. Sheahen's relentless efforts, prosecutors were forced to drop all charges against Mrs. Goodman.