WASHINGTON — Rayful Edmond, a drug kingpin once believed to control about a third of the cocaine trade in the nation’s capital during the crack epidemic of the 1980s, has died in federal custody, the Bureau of Prisons confirmed Tuesday. [time-brightcove not-tgx=”true”] Edmond, 60, was known at the height of his criminal empire as the “king of cocaine” in Washington, D.C.