PITTSBURGH — Forty years before Robert Bowers was accused of gunning down 11 people in an anti-Semitic rampage at the Tree of Life synagogue, the man believed to be his father was charged with raping a stranger and later committed suicide, according to court records unsealed on Friday.

The alleged attack was about a mile from where the synagogue massacre took place.

The court documents add a new shard in the fragmented, solitary life of Mr. Bowers, 46, who pleaded not guilty in the killings this week. The records were sealed by a judge on Thursday after a request from the Allegheny County district attorney’s office, but were then made public after The New York Times and other news media outlets petitioned a Pennsylvania court for their release.

Mr. Bowers would have been about 6 years old on the night in April 1979 when the police in Pittsburgh received a call reporting the sound of screaming and, according to records, found Randall G. Bowers sexually assaulting a woman in Squirrel Hill — the same neighborhood where the Tree of Life attack occurred last Saturday.

Public records, including a marriage license, indicate that Randall Bowers was the father of Robert Bowers. Relatives have declined to confirm the family relationship or discuss the family’s history.