Kerry Thornley began writing at the age of 14. He sold his first piece of work to a local newspaper when he was 19 and sold many short stories, articles, and poems during his life. While attending high school in Whittier, California (home of Richard Nixon), Thornley won a number of public -peaking competitions, including the Voice of Democracy competition.

After attending the University of Southern California for one year as a journalism student, he decided to fulfill a two-year active-duty assignment (assumed earlier when he joined the marine corps reserve). He was assigned to El Toro Marine Air Station in Santa Ana, California, where he was to meet Lee Harvey Oswald. Later Thornley served in the Far East, in the First Marine Aircraft Wing, and distinguished himself again as a public speaker on political/philosophical issues by winning first place in the Wing Technique of Instruction competition. He was therefore sent to Washington, D.C., to appear in the finals.

It was shortly after his return to overseas duty that Thornley read in a newspaper of Oswald's defection to Russia and, as a result, began work on his first novel, The Idle Warriors, featuring a protagonist modeled after Oswald.

After leaving the marine corps, Thornley moved to New Orleans to finish The Idle Warriors and to gain background material for future writings. Just a few days after the assassination of JFK, Thornley's book was highlighted in New Orleans newspapers as being a key to understanding the "assassin," Lee Harvey Oswald.

Some researchers have speculated that Thornley may have associated with both Lee and Marina while in New Orleans. There is even a claim that Thornley and Marina were having an affair. Whatever the truth, there is no doubt that Thornley was close to certain assassination players.