A friend of Perry's from a previous incarceration. Perry considers Willie-Jay to be a true kindred spirit, a smart man. Perry's desire for a relationship like the one he had with Willie-Jay leads him to begin his journey with Dick.
A former cell mate of Dick Hickock and a former ranch hand of Herbert Clutter, Floyd becomes a catalyst for the murders by allowing Dick to believe that the Clutters had a safe in the house. The murders take place ten years after Dick and Floyd share a cell, but Wells becomes the only person who can tie the murders to Dick and Perry.
Nancy's best friend, and one of the last people to see the Clutters alive, Susan discovers the bodies after the family is killed. Her grief causes her for form an intense bond with Bobby soon after the murders.
Nancy Clutter's long-time boyfriend, he is the very last person, except for the killers, to see the Clutter's alive. Bobby becomes the main person of interest following the killings.
The youngest member of the investigation team, he discovers most of the evidence, including the gun, and Perry's belongings.
A friend of Perry's from the army who comes to provide companionship and sympathy for Perry after his arrest.
George Ronald York
A prisoner on death row with Dick and Perry who went on a mass killing spree over several states with James Douglas Latham.
James Douglas Latham
George's accomplice on the killing spree, James is another prisoner on death row with Dick and Perry.