Brian Branch-Price, Pool, File, Associated Press
FILE - In this 1996 file photo, Thomas Capano leaves Superior Court in Wilmington, Del., after being sentenced to death for the murder of Anne Marie Fahey. Capano, a once wealthy and politically connected attorney serving life in prison for killing Fahey, was found dead in his prison cell on Monday Sept. 19, 2011.

DOVER, Del. — Tom Capano, a once wealthy and politically connected attorney in Delaware who was serving life in prison for killing a mistress in 1996, was found dead in his prison cell Monday, authorities said.

Capano, who spent time on death row before his death sentence was overturned by the state Supreme Court in 2006, was found unresponsive Monday in his cell at the state prison in Smyrna. He was pronounced dead at 12:34 p.m., according to a state official.

Capano, 61, had been in ill health for some time, and authorities do not suspect foul play in his death. At a 2006 court hearing where he was told he would spend the rest of life in prison after prosecutors decided not to seek a new death penalty hearing, he appeared pale and severely bloated.

Capano was convicted in 1999 of shooting his mistress, Ann Marie Fahey, after she decided to end an affair with him. Fahey, 30, was the scheduling secretary to then-Gov. Tom Carper, now Delaware's senior U.S. senator.

Fahey's body was never found. Prosecutors said Capano stuffed her body inside a cooler and dropped it in the Atlantic Ocean.

Fahey's oldest brother, Robert Fahey, said Capano's death was "long overdue."

"He killed Anne Marie, he murdered Anne Marie, 15½ years ago," Fahey said. "He had the benefit of solitary confinement for 15 years. She was robbed of her life, so it was clearly long overdue."

"Given that he never atoned for his sins, he never admitted he was guilty and he ruined many people's lives, my guess is that he went straight to hell, and that's where he belongs," Fahey added.

The state Supreme Court vacated Capano's death sentence in January 2006 as the result of a 2002 U.S. Supreme Court ruling in Ring v. Arizona, when Capano's petition before the nation's high court was pending.

In the ruling, the Supreme Court held that juries, not judges, must decide whether a defendant is eligible for the death penalty. Capano's lawyers argued that his death sentence should be overturned because the jury's vote for death sentence eligibility was not unanimous. Capano's jury voted 11-1 in determining that Fahey's murder was the result of "premeditation and substantial planning," a statutory aggravating circumstance that made him eligible for the death penalty.