Habeas Corpus
A legal procedure that allows prisoners to challenge the legality of their detention. Under federal law, it can only be invoked for constitutional violations, not for errors in state law application.
Due Process Clause
Part of the Constitution that ensures fair procedures before depriving a person of life, liberty, or property. It requires that legal proceedings be conducted fairly and that individuals have the opportunity to be heard.
"Some Evidence" Standard
A legal threshold used by parole boards to determine if there is enough evidence to consider an inmate unfit for parole. In California, this standard was central to the parole decisions challenged in this case.
Liberty Interest
A protected right under the Due Process Clause that pertains to an individual's entitlement to freedom from government interference in certain areas, such as the possibility of parole.