Demara, known locally as ‘Fred’, was born in Lawrence, Massachusetts, in 1921, at 40 Texas Avenue in the lower southwest Tower Hill Neighborhood. His father, Ferdinand Waldo Demara, Sr. was born in Rhode Island and worked in Lawrence’s old Theatre District as a motion picture operator. In those days, his father did financially well and they lived on Jackson St in Lawrence, an upper class district with many larger-size, finer homes. However it was his uncle, Napoleon Louis Demara, Sr. who owned those theatres, where Fred’s father, Ferdinand, Sr. was an active union member. At some point during the earlier stages of the 1930s depression, Fred’s father lost virtually all he had and the family moved to poorer districts in the city. This angered the young man.  He ran away from home at the age of sixteen to join Cistercian monks in Rhode Island, where he stayed for several years. He joined the U.S. Army in 1941.

The following year Demara began his new lives by borrowing the name of Anthony Ignolia, an army buddy, and going AWOL. After two more tries in monasteries he joined the Navy. He did not reach the position he wanted, faked his suicide and borrowed another name, Robert Linton French, and became a religiously-oriented psychologist. He taught psychology at Gannon College (now a university) in Erie, Pennsylvania, served as an orderly in a Los Angeles sanitarium, and served as an instructor in St. Martin’s College (now a university) in the state of Washington. The FBI caught him eventually and he served 18 months in prison for desertion.  After his release he assumed a fake identity and studied law at night at Northeastern University, then joined the Brothers of Christian Instruction in Maine, a Roman Catholic order.

While at the Brothers of Christian Instruction, he became acquainted with a young doctor named Joseph C. Cyr. That led to his most famous exploit, in which he masqueraded as Cyr, working as a trauma surgeon aboard HMCS Cayuga, a Royal Canadian Navy destroyer, during the Korean War. He managed to improvise successful major surgeries and fend off infection with generous amounts of penicillin. His most notable surgical practices were performed on some sixteen Korean combat casualties who were loaded onto the Cayuga. All eyes turned to Demara, the only “surgeon” on board, as it became obvious that several of the casualties would require major surgery or certainly die. After ordering personnel to transport these variously injured patients into the ship’s operating room and prep them for surgery, Demara disappeared to his room with a textbook on general surgery and proceeded to speed-read the various surgeries he was now forced to perform, including major chest surgery. None of the casualties died as a result of Demara’s surgeries. Apparently, the removal of a bullet from a wounded man ended up in Canadian newspapers. One person reading the reports was the mother of the real Joseph Cyr; her son at the time of “his” service in Korea was actually practicing medicine in Grand Falls, New Brunswick. When news of the impostor reached the Cayuga, still on duty off Korea, Captain James Plomer at first refused to believe Demara was not a doctor (and not Joseph Cyr). The Canadian Navy chose not to press charges, and Demara returned to the United States.

During one of his impersonations, as Brother John Payne of the Christian Brothers of Instruction (also known as Brothers of Christian Instruction), Demara came up with the idea of making the religious teaching order more prominent by founding a college in Alfred, Maine. Demara proceeded on his own and actually got the college chartered by the state. He then promptly left that religious order in 1951 when the Christian Brothers of Instruction offended him by not naming him as rector or chancellor of the new college and also chose what Demara considered was a terrible name for the college. The college Demara founded, LaMennais College in Alfred, Maine, existed from 1951 (when Demara left) through 1959 when it moved to Canton, Ohio, and in 1960 changed its name to Walsh College (now Walsh University).

After this episode, he sold his tale to Life and worked in short-term jobs, since he was now widely known. He resorted to drinking. Only after he returned to his old tricks and got fake credentials could he get another job at a prison in Huntsville, Texas. According to his biographer, Demara’s past became known and his position untenable when an inmate found a copy of Life with an article about the impostor.  Demara appeared on the November 12, 1959, episode of the TV quiz program You Bet Your Life, hosted by Groucho Marx. He recounts his exploits. He said that the $1,000 he earned on the program was going to be donated to the „Feed and Clothe Fred Demara Fund”.  Demara continued to use new aliases but, as a result of his self-generated publicity, impersonation was harder to accomplish than before. In 1960, as a publicity stunt, Demara was given a small acting role in the horror film The Hypnotic Eye. He appears briefly in the film as a (genuine) hospital surgeon. By this point, Demara’s girth was so notable that he could not avoid attracting attention. Demara had already been considerably overweight during his impersonation of Cyr.

In the early 1960s Demara worked as a counselor at the Union Rescue Mission in downtown Los Angeles. In 1967 Demara received a graduate certificate in Bible from Multnomah Bible College in Portland, Oregon.  Demara had various friendships with a wide variety of notable people during his life. This included a close relationship with actor Steve McQueen, to whom Demara delivered last rites in November 1980.  When Demara’s past exploits and infamy were discovered in the late 1970s, he was almost dismissed from the Good Samaritan Hospital of Orange County in Anaheim, California, where he worked as a visiting chaplain. Chief of Staff Philip S. Cifarelli, who had developed a close personal friendship with Demara, personally vouched for him and Demara was allowed to remain as chaplain. Demara was a very active and appreciated minister, serving a variety of patients in the hospital. Few of those with whom he interacted at the hospital knew of his colorful past. Due to limited financial resources and his friendships with Cifarelli and Jerry Nilsson, one of the major owners of the hospital, Demara was allowed to live in the hospital until his death, even after illness forced him to stop working for them in 1980.  Demara died on June 7, 1982, at the age of 60 due to heart failure and complications from his diabetic condition, which had required both of his legs to be amputated. According to his obituary in The New York Times, he had been living in Orange County, California, for eight years. He died at Nilsson’s home in Anaheim, California.