UNIONTOWN, Pa.—A man already serving up to 20 years in prison for attempted rape had four more years tacked onto his sentence for sending letters threatening to kill the victim, judge and district attorney and to blow up the western Pennsylvania courthouse where he pleaded guilty.

Thirty-four-year-old Robert Ray Shaner, formerly of Mount Braddock, was sentenced after pleading guilty in Fayette County on Monday.

Shaner acknowledged sending the letters in August 2011 to now-retired Fayette County Judge Ralph Warman and District Attorney Jack Heneks from a state prison in Luzerne County

Shaner had previously claimed he's innocent and pleaded guilty to the knifepoint rape attempt only because he was taking seizure medication, and contends he's a homosexual incapable of trying to rape a woman..

His total combined sentence is now 7 years, 4 months to 24 years in prison.