Mr. Killen was a founding member of the Klan in the Philadelphia area and its chief recruiter, according to the F.B.I. He had been among 18 men tried in 1967 on federal charges of conspiring to violate the civil rights of Mr. Chaney, Mr. Goodman and Mr. Schwerner, who were shot to death on the night of June 21, 1964. Their bodies were found six weeks later, buried under an earthen dam on a nearby farm, during an extensive search led by the F.B.I.
The federal charges against Mr. Killen, a sawmill operator and part-time preacher at small churches near his lifelong home in Union, Miss., were dismissed after a lone member of the all-white jury at the 1967 trial in Meridian held out for acquittal, saying that she did not believe a man of God could have participated in such a crime.
Mr. Killen, known to friends as Preacher Killen, continued to live with his wife, Betty Jo, at their modest ranch home near his 20-acre farm and sawmill. He resumed his preaching and displayed a tablet with the Ten Commandments on his lawn.
But in 1975 he was charged with making a telephone call threatening to kill a private investigator who had been hired by a man to follow the man’s wife, who he believed was having an affair with Mr. Killen.
Mr. Killen was sentenced to five months in prison in the case, which was prosecuted by Marcus D. Gordon, the Neshoba County district attorney at the time and later the judge who presided over the murder trial.
Mr. Killen was indicted by a Neshoba County grand jury on murder charges in January 2005. Two months later, free on bail, he broke both his legs when a tree at his farm fell on him. He sat in a wheelchair during his state trial in Philadelphia while recovering from his injuries, a gaunt figure sometimes breathing through tubes attached to an oxygen tank.
The murder prosecution, brought by the Mississippi state attorney general, Jim Hood, and the county district attorney, Mark Duncan, was based largely on the transcripts of testimony at the federal trial.
Mr. Killen was said to have recruited the mob that killed the civil rights workers, although he was not at the scene of their murders, having gone to a funeral home to attend two wakes. In testimony, fellow Klansman said he had gone to the funeral home to create an alibi for his whereabouts when the…