For Ben Greenberg, unraveling unsolved civil rights murders is both a professional endeavor and a personal calling. Ben’s interest in the civil rights movement was triggered in part by his research into the life of his own father, Paul A. Greenberg, who had been a special assistant to the Rev. Martin Luther King Jr. at the Southern Christian Leadership Conference in the early 1960s. Greenberg’s pursuit of that history has led him straight to the heart of the enduring mysteries that surround many unsolved murders in Southwest Mississippi, where Ku Klux Klan activity was especially virulent. For the past two years, Greenberg has been investigating cases from that area, including the 1964 murder of Clifton Walker, a black man who was shot in his car on a country road in Woodville, Mississippi.