The castle left the hands of the Paterson family in 1946, after the death of Colonel Adrian Gordon Paterson, when his wife sold the castle to the government. In 1947, the castle was refurbished and became a borstal, then a young offenders' institution before becoming an open prison for adult male prisoners. It is now known as "HMP Castle Huntly" and is the only open prison in Scotland. Most prisoners at the establishment are low-risks serving short sentences of up to two years, although some are long-sentence prisoners approaching the end of their sentences.