Arridy had spent most of his life at the Colorado State Home and Training School for Mental Defectives; he couldn’t even count to five or tell the difference between red and blue. He was picked up by police after wandering around rail yards in Cheyenne, Wyoming, and was thrown into the centre of the investigation of the slayings. After an intensive interrogation, Arridy was led into a false confession by Sheriff George J. Carroll, the officer who had a part in breaking up the Ma Barker gang. Many theorise that Carroll framed Arridy in an attempt to get his name in the papers again. “I think he had to get famous again,” said author Robert Perske. According to Carroll, Arridy had provided a detailed account into the slaying despite the fact that he could barely string a coherent sentence together.

He was found guilty despite the fact that there was no direct evidence that could tie him to the crime. In fact, they already had a prime suspect: Frank Aguilar who had been fired by Riley Drain, the father of Barbara. The murder weapon was even discovered in Aguilar’s home but after arresting Arridy and discovering he was from Pueblo, they zoned in on him. During the trial, Aguilar claimed that it was Arridy who killed Dorothy even though her sister, who survived the attack, pointed at Aguilar as their attacker. Both Arridy and Aguilar were sentenced to die in the gas chamber. Arridy would become known as the happiest man ever to be on Death Row.

Roy Best, the warden, lobbied tirelessly to save Arridy’s life. He visited him daily on Death Row and have gim a red toy train to play with. “He was as happy as any child with something he always had longed for and never expected to have,” said Best. On Christmas Eve of 1938, Best even brought Arridy home to play with his nephews. He – as well as most other people – knew that Arridy was truly innocent of the crime for which he had been charged. On the 6th of January, 1939, Arridy was led to the gas chamber with his toy train still in his hand. “A wreck! A wreck! Fix the wreck,” Arridy cried out with glee as he played with his train one last time, pretending to crash it into the cell door. He requested ice cream as his last meal and didn’t comprehend that he was about to die. He didn’t even understand the meaning of the gas chamber, telling the warden: “No, no, Joe won’t die…”

He stepped into the gas chamber grinning like a little boy. He was strapped to the death chair and a blindfold placed over his eyes. “Goodbye, Joe,” said Father Schaller before slipping out. Then Roy Best dropped the gas cylinders that ended his friend’s life – as warden at Old Max, that was his job.

Joe Arridy was buried on Woodpecker Hill, the rocky western slope of Greenwood Cemetery which was reserved for convicts who died in nearby Canon City prisons with no loved ones to bury them. His name was spelt wrong on the rusty marker placed on top of his grave. Years later, this marker would be exchanged for a granite monument which had been purchased by advocates for the developmentally disabled. “Developmentally disabled people routinely say ‘yes’ to authority figures,” said Craig Sevara, advocacy specialist for the Arcof the Pikes Peak Region during the unveiling of the new monument. “They are extremely vulnerable to abuse and exploitation.” The new monument reads: “Here lies an innocent man.”

In 2011, Arridy was granted a full and unconditional posthumous pardon. An overwhelming body of evidence indicated that he was innocent, including a coerced and false confession and the likelihood that Arridy wasn’t even in Pueblo at the time of the slaying. “Pardoning Mr. Arridy cannot undo this tragic event in Colorado history. It is in the interests of justice and simple decency, however, to restore his good name,” said Gov. Bill Ritter.