In Edwards v. Balisok (1997) 520 U.S. 641 117 S. Ct. 1584, 137 L. Ed. 2d 906, a good time credits case, the inmate contended the "some evidence" standard was inadequate for reviewing his claim that the hearing officer was biased and had deceitfully deprived him of a chance to present exculpatory evidence. The court held that the scope of judicial review in prison discipline cases is not so cramped. Even the minimum due process standards applied to prison disciplinary hearings "are not so lax as to let stand the decision of a biased hearing officer who dishonestly suppresses evidence of innocence." ( Id. at p. 647 117 S. Ct. at p. 1588.) The court explained that the "some evidence" standard applies only to questions of evidentiary sufficiency. It is an additional requirement of due process, not a substitute for other established due process requirements. ( Id. at p. 648 117 S. Ct. at p. 1588.) When a claim is based on an argument that the procedures resulting in prisoner discipline were not valid, then, as a predicate to such a claim, the administrative determination must have been previously invalidated. In Edwards, the claim for declaratory judgment was brought as part of a section 1983 suit.