He was manipulated by the police to make a false confession due to his mental incapacities. Arridy was mentally disabled and was 23 years old when he was executed on January 6, Many people at the time and since maintained that Arridy was innocent.
A group known as Friends of Joe Arridy formed and in commissioned the first tombstone for his grave. They also supported the preparation of a petition by David A. Martinez, Denver attorney, for a state pardon to clear Arridy's name. Another man, Frank Aguilar, was convicted and executed for the same crime two years before Arridy's execution. In , Arridy received a full and unconditional posthumous pardon by Colorado Governor Bill Ritter 72 years after his death.
Ritter, the former district attorney of Denver, pardoned Arridy based on questions about the man's guilt and what appeared to be a coerced false confession. The couple were first cousins and did not speak English. Henry took a job as a molder with a Colorado Fuel and Iron steel mill in Pueblo that he learned was hiring workers. John Arridy, the eldest of the couple's three surviving children, was non-verbal for the first five years of his life and only spoke in short simple sentences.
Even as an adult, he generally did not talk at all unless spoken to first. After he attended one year at Bessemer Elementary School, his principal told his parents to keep him at home, saying that he could not learn. Arridy did not socialize with other children in his neighborhood, instead preferring to wander town, hammer nails, and make mud pies , a habit he kept up into his mid-teens. In , Henry Arridy lost his job and appealed to neighbors to help him write letters to find a place for his son, as Henry was partially illiterate able to read, but not write.
It was noted during formal psychological exams, including a Binet-Simon test , that Arridy was "extremely concrete in his thinking and totally unable to think abstractly about anything", noting he could not tell the difference between a stone and an egg or wood and glass, with other examples including his inability to count past five without assistance, tell apart colors, or name the weekdays.
