Epstein obtained his degree in Government from Cornell University. One of his professors at Cornell was Vladimir Nabokov, for whom Epstein worked part-time advising the writer on which recently released films he should see. In 1973, he received his Ph.D in government from Harvard University. He did his master's thesis on the search for political truth which later became a top-selling book.
Edward Jay Epstein taught courses at these universities for three years. While a graduate student at Cornell University in 1966, he published the book Inquest, an influential critique of the Warren Commission probe into the John F. Kennedy assassination. After teaching at Harvard, UCLA, and MIT, Epstein decided to pursue his writing career back in New York City.
In 2017, Edward Jay Epstein was the subject of a documentary, Hall of Mirrors, directed by the sisters Ena and Ines Talakic.
Epstein wrote three books about the Kennedy assassination, eventually collected in The Assassination Chronicles: Inquest, Counterplot, and Legend (1992). His books Legend (1978) and Deception (1989) drew on interviews with retired CIA Counterintelligence Chief James Jesus Angleton, and his 1982 book The Rise and Fall of Diamonds was an exposé of the diamond industry and its economic impact in southern Africa.
In Have you ever tried to sell a diamond (1982), Edward Jay Epstein detailed the heavy marketing strategy used by the diamond company De Beers to turn tiny rocks of transparent crystalized carbon into highly-demanded, high-priced mass market items.
In his 1996 book The Secret History of Armand Hammer, the author revealed, among many other things, how the prolific businesssman laundered money to finance espionage for the Soviets in the 1920s and 1930s.
Epstein gets many facts about surveillance issues wrong, calling into question his competence to serve as a guide to thinking seriously about the Snowden saga. He gets dates wrong, calls an important technology by the wrong name, and inaccurately describes various programs and a presidential directive Snowden leaked.