"Federal Bureau of Prisons director Norman Carlson argued for the creation of a new type of facility where the most dangerous, uncontrollable inmates could be isolated from correction officers and other prisoners for security and safety.
Under his guidance, Marion Penitentiary was operated in "permanent lockdown" for the next two decades. It became a model for the design of ADX as a control unit prison. Carlson said that such a prison would hold criminals desperate enough to murder corrections officers or other inmates in the hopes of being sentenced to death.
He argued that as draconian as these measures were, they were the only way to deal with inmates who have "absolutely no concern for human life.""