Ryan first served prison time at Bendigo Prison. Here, under Ian Grindlay (who would later become the Governor of Pentridge Prison), he appeared to want to rehabilitate himself. His time in prison was productive and he exhibited a disciplined approach to study, completing his Leaving Certificate (the equivalent of 11 years of formal schooling). He was studying for his Matriculation (the successful completion of 12 years of formal schooling) when he was released on parole in August 1963. He was regarded by the authorities as a model prisoner.