Clayton Fountain (September 12, 1955 – July 12, 2004) was a former federal prisoner, member of the Aryan Brotherhood, and convicted murderer. Clayton Anthony Fountain was born on September 12, 1955, at the U.S. Army Hospital in Fort Benning, Georgia. Clayton was the oldest of six children, having one brother and four sisters, and was named after his father, Clayton Raleigh Fountain. The family moved every 1½ to 2 years. While his father served combat tours in Korea and Vietnam and his mother was working, Clayton, as the oldest child in family, became a surrogate for both parents when he was very young. He recalls maternal responsibilities for cooking, ironing, serving, cleaning, and caring for his young siblings. It was the male/paternal role, however, for which his father had carefully trained him. While serving in the Marines, he was convicted of murdering his staff sergeant in 1974, while stationed in the Philippines. He was sentenced to life imprisonment, and was ultimately sent to the United States Penitentiary, Marion, which was at the time, the highest-security prison in the nation. Fountain used his military training to murder three prisoners and one correctional officer with a home made knife while serving time at Marion, and was labeled the “Most Dangerous Prisoner” in the federal system.

After stabbing an officer to death in 1983, Clayton Fountain was moved to the United States Medical Center for Federal Prisoners in Springfield, Missouri. He was housed in a specially constructed containment unit, and was only allowed contact with authorized personnel. Fountain converted to Catholicism, and completed several educational courses on theology during the twenty years he spent in virtual isolation. He developed ties with an order of Trappist monks, and was accepted posthumously as a lay brother after his unexpected death from a heart attack in 2004. The book A Different Kind of Cell: The Story of a Murderer Who Became a Monk is based on his life and religious conversion.