William F. Pepper, 86, Dies; Claimed the Government Killed Dr. King

William F. Pepper, who was the central figure in a decades-long effort to prove that the Rev. Dr. Martin Luther Jr. was killed not by a lone gunman but by a vast government plot, a controversial stance that made him something of a celebrity among the country’s teeming subculture of conspiracy theorists, died on April 7 in Manhattan. He was 86.His wife, Mina Nguyen-Pepper, said the cause of his death, in a hospital, was pneumonia. He lived in Manhattan.James Earl Ray shot and killed Dr. King in Memphis on April 4, 1968. He was arrested two months later at Heathrow Airport in London, just…