Earl Warren,
Townsend v. Sain — Opinion of the Court
“ Where newly discovered evidence is alleged in a habeas application, evidence which could not reasonably have been presented to the state trier of facts, the federal court must grant an evidentiary hearing. Of course, such evidence must bear upon the constitutionality of the applicant's detention; the existence merely of newly discovered evidence relevant to the guilt of a state prisoner is not a ground for relief on federal habeas corpus. Also, the district judge is under no obligation to grant a hearing upon a frivolous or incredible allegation of newly discovered evidence. ”
