The Prison Policy Initiative published a brief on May 21, 2020 that explores how parole “program requirements”, often delayed during the COVID-19 pandemic, keep prisoners locked up who could safely be released.
As the briefing notes:
These are the people who have already been granted parole by the state parole boards, but have not yet taken a class or program that the parole board requires them to complete before they can go home. They are near enough to the end of their sentences to be parole-eligible, and the parole board has determined that they are “safe” to return to the community, but they cannot be released until they complete a program, often a drug and alcohol treatment program.
Read more: https://www.prisonpolicy.org/blog/2020/05/21/program-requirements/