You might say that Floyd Wells planted the seed that grew into the plot to murder the Clutter family. He was the prison cellmate who told Dick Hickock about his time working on the Clutter farm and how Mr. Clutter kept thousands of dollars in his home safe. When he got out of prison, Hickock and Perry Smith decided to steal that money and leave no witnesses. There didn't get the money, but they did kill the family.
When he heard about the Clutter murders, Wells, who was still in prison, felt guilty about talking to Hickock and informed the warden about what happened. He cooperated with the FBI, who had no suspects. Wells collected a $1,000 reward and early release from prison for his information.
Willy Jay was a fellow inmate and assistant to the chaplain at Kansas State Penitentiary. Perry Smith looked up to him as a mentor and greatly admired him; their relationship may have been more intimate. There is some speculation that Capote, the author of "In Cold Blood," invented this character. I have not been able to find any other information about him.
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