Raymond Jessie Marcus was born in Los Angeles in 1927. He grew up in its largely working-class Jewish section of Boyle Heights. He later recalled: "Our neighborhood was a smaller - population wise - version of New York's lower east side, with much intellectual and political ferment."

The Marcus family were very interested in politics and Ray remembers being taken to meetings in support of the Popular Front government during the Spanish Civil War. He was ten years old at the time. Ray Marcus also became aware of Adolf Hitler: "I remember listening to Hitler's hysterical-sounding, Jew-hating speeches with my family on short-wave radio."

After graduating from high school, Marcus volunteered for military service in the Second World War. He joined the Army Air Corps and left in 1947. He attended business school and by the early 1950s he was running a small factory in Los Angeles manufacturing vinyl plastic items for household use. One of the men he employed was his friend, the blacklisted screenwriter, Bernard Gordon: "Ray hired me for $50 a week as a salesman, needing sales to build his business and to help me deal with unemployment. Unfortunately, the marriage of true need and good intentions was less than successful. I was surely one of the world's worst salesmen. I drove around to the scattered department and notions stores in the vast Los Angeles area and tried to persuade the owners or buyers that they needed Ray's plastic merchandise."

Marcus also agreed to become Gordon's front-man for films that he was working on. Movies made with the name, "Raymond T. Marcus" on the script included Earth vs. the Flying Saucers, (1953), Hellcats of the Navy (1957), The Man Who Turned to Stone (1957), The Dead That Walk (1957), Chicago Confidential (1957), Escape from San Quentin (1957) and The Case Against Brooklyn (1958).

Marcus was one of those who found it difficult to believe that Lee Harvey Oswald was the lone-gunman involved in the assassination of John F. Kennedy. On 29th December, 1963, he wrote to Earl Warren, who had recently been named to head the presidential commission investigating the assassination: "I write as a citizen who, like most other Americans, has still not recovered from the shocking and tragic events of that terrible weekend of November 22. The shock and grief have been augmented by anger and bewilderment at the amazing mass of contradictory statements which have come from the Dallas police and, reportedly, from the FBI, which are continuing up to the present time."

Marcus was a regular reader of I. F. Stone's Weekly. He was therefore dismayed when I. F. Stone supported the conclusions of the Warren Commission Report by pointing out that "I believe the Commission has done a first-rate job, on a level that does our country proud and is worthy of so tragic an event. I regard the case against Lee Harvey Oswald as the lone killer of the President as conclusive." However, as John Kelin has pointed out, at the time Stone wrote this article: "the Warren Report had just been published and the twenty-six volumes of supporting evidence and testimony were still not available".

Stone then went on to criticize those who had argued that there had been a conspiracy. After attacking the work of Mark Lane he turned on Bertrand Russell, who he described as "my dear and revered friend". He suggested that Russell had dismissed the conclusions of Warren Commission report without even reading it. This was completely untrue. As Russell's assistant, Ralph Schoenman, later pointed out, he had been provided a copy of the report a week before its official release date.

Stone then went onto to look at the two books by Joachim Joesten and Thomas G. Buchanan, that had already been published arguing that there had been a conspiracy: "The Joesten book is rubbish, and Carl Marzani - whom I defended against loose charges in the worst days of the witch hunt - ought to have had more sense of public responsibility than to publish it. Thomas G. Buchanan, another victim of witch hunt days, has gone in for similar rubbish in his book, Who Killed Kennedy? You couldn't convict a chicken thief on the flimsy slap-together of surmise, half-fact and whole untruth in either book… All my adult life as a newspaperman I have been fighting, in defense of the Left and of a sane politics, against conspiracy theories of history, character assassination, guilt by association and demonology. Now I see elements of the Left using these same tactics in the controversy over the Kennedy assassination and the Warren Commission Report."

Ray Marcus, who had subscribed to I. F. Stone's Weekly since its first edition in January 1953, was deeply shocked by this article. Marcus later recalled: "What was totally lacking in I. F. Stone's comments was any evidence of the critical analysis he normally employed on assessing official statements." On 8th October, 1964, Marcus wrote Stone a long letter outlining the flaws in the Warren Report. Marcus argued that in order to accept the Warren Commission's lone-gunman scenario, one must accept fifteen points as true. These points were explained in an eight page letter. Marcus never received a reply.