The day was September 20, 1958. Dr Martin Luther King, Jr., then 29, was in a Harlem department store, signing copies of Stride Toward Freedom, his account of the 1955 Montgomery Bus Boycott which he led. He was suddenly approached by a 42-year-old well-dressed woman, who asked him: “Are you Martin Luther King?” “Yes,” King replied, without looking up from where he was signing his book. The stylishly dressed woman, who would later be identified as Izola Ware Curry, said: “I’ve been looking for you for five years,” and plunged a 7-inch, ivory-handled steel letter opener into King’s chest. Curry...