In the case of Morrissey et al. v. Brewer, Warden, et al., 1971, the U.S Supreme Court ruled that parolees have a right to due process before their parole can be revoked. The court held that while states are not required to provide parole systems, if they do so then certain minimum procedures must be followed when revoking an individual's parole status. These include written notice of claimed violations; disclosure of evidence against them; opportunity for being heard in person and presenting witnesses and documentary evidence; neutral hearing body; right to confront and cross-examine adverse witnesses (unless there is good cause for not allowing confrontation); a "written statement by the factfinders as to the evidence relied on and reasons" for revoking parole; availability of counsel under certain circumstances.

The dissenting opinion in the Morrissey v. Brewer case argued that parole revocation should not be treated as a criminal prosecution, and therefore does not require all the same constitutional protections. The dissenters believed that parole is an act of leniency, allowing prisoners to serve part of their sentence outside prison walls under certain conditions. If those conditions are violated, it's reasonable for the state to return them to prison without a full trial-like hearing. They also expressed concern about burdening already overloaded parole systems with additional procedural requirements which could potentially discourage states from offering parole at all.