Actor Woody Harrelson's father, Charles Harrelson, has died of a heart attack in the Supermax federal prison in Colorado.
Charles Harrelson -- who was 69 -- was serving two life sentences there for the murder of a federal judge in Texas.
A Bureau of Prisons spokeswoman says that Harrelson was found unresponsive in his cell on the morning of March 15th.
Fremont County Coroner Dorothy Twellman said an autopsy showed Harrelson had severe coronary artery disease. She said he probably died in his sleep.
Charles Harrelson was convicted of murder in the May 1979 slaying of U.S. District Judge John Wood Junior outside his San Antonio home. Prosecutors said a drug dealer hired him to kill Wood because he did not want the judge to preside at his upcoming trial.
Charles Harrelson denied the killing, saying he was in Dallas, 270 miles away, at the time.
Wood, known as "Maximum John" for the sentences he gave in drug cases, was the first federal judge to be killed in the 20th century.
His son got his start in acting as Woody the bartender on "Cheers" in 1985 and went on to star in films.
The actor was just seven when his father was first sent to prison, for murdering a Texas businessman. He was in college when his father was convicted of the judge's assassination.