William Prater; Jailed for Life in Unionist’s Murder

William Jackson Prater, a former United Mine Workers official who was serving a life term in prison for his role in the 1969 slayings of union dissident Joseph (Jock) Yablonski and his family, died in his cell Friday, officials said.

Prater was found early in the morning at the State Correctional Institution at Dallas in Luzerne County. A prison spokesman said Prater, who was 70, apparently died of natural causes.

“He had been in poor health for some time,” Roy VanWhy said. Prater had been confined to a wheelchair since suffering a stroke in 1983.

Prater was sentenced in 1973 and was serving three life sentences for the murders.

Yablonski, 59, was shot to death along with his wife, Margaret, 57, and their 25-year-old daughter, Charlotte, at their Clarksville home in southwestern Pennsylvania on New Year’s Eve, 1969. Yablonski had lost an election for UMW president earlier that December.

His opponent, then-incumbent UMW President W. A. (Tony) Boyle, was later convicted of ordering the assassination. Boyle’s first conviction was overturned and he was convicted a second time. He died in May, 1985, while serving three life terms.

Prater, formerly of LaFollette, Tenn., was a mid-level union official accused of helping to plan the killing and accumulating $20,000 in union funds to pay the assassins. He later helped prosecutors convict Boyle.

The three men accused of carrying out the killings, Aubran (Buddy) Martin, Claude Vealey and Paul Gilly, were all convicted and sentenced to life in prison.

Prater served 16 years in a federal prison before being paroled, but then was transferred to the state prison at Pittsburgh in September, 1988, to serve life terms imposed under state law and was moved to Dallas later that year.