Petitions are those in which inmates may collaterally challenge their convictions (after exhausting all available state remedies to do so) by arguing that their trial was constitutionally defective.

I believe the answer is: Habeas corpus

Habeas corpus petition would eventually develop into a legal battle between the states vs the defendants, and would be considered to be a civil class action. This type of petittion usually occurs when there is a proof that a certan legal departement is abusing its power of there is a new development regarding an interpretation of law.