Lane, the unappeasable people's tribune, and fringe comic Dick Gregory don't buy the story that James Earl Ray alone engineered the murder of Martin Luther King and, according to national polls, most people share their skepticism. Gregory contributes little here besides some emotional memories of the martyr Martin. Lane, however, has dug deeply into the Memphis murder and uncovered a series of implausibilities which may or may not be as sinister as he paints them. The documentation of the FBI vendetta against King is not new, though the flashy ""Zorro""--the code assigned to anti-King plotting--conjures up that agency's Dick Tracy mentality. Lane is most unsettling in his minute reconstruction of the events of April 4, 1968. Why was the black detective charged with security at the ill-fated Lorraine Motel pulled off his job two hours before the assassination? Why were black firemen in the vicinity reassigned? Arguing that Ray was ""induced to plead guilty"" by lazy, ill-prepared counsel Percy Foreman, Lane goes on to charge that the hard evidence--ballistics and fingerprints--was ""minimal"" and would never have stood up under cross-examination. Not one to go halfway, Lane doesn't stop at implicating the Memphis police and the FBI; he makes unsavory allegations about Ray's lawyers, judges, and biographers, scoring especially William Bradford Huie's He Slew the Dreamer (originally titled They Slew the Dreamer) and George McMillan's recent well-received The Making of an Assassin (1976). Lane's trepidations extend right up to the currently convening Select Committee on Assassinations. He won't necessarily convince you of anything--he puts forth no cogent theory of his own beyond FBI complicity. But for finding loose ends, improbable coincidences, and shoddy police work, there is no one who equals his intemperate tenacity.