H

 Under Townsend v. Sain, 372 U. S. 293, 317 (1963), '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.' See 954 F. 2d, at 1034. 

A person when first charged with a crime is entitled to a presumption of innocence, and may insist that his guilt be established beyond a reasonable doubt. In re Winship, 397 U. S. 358 (1970). Other constitutional provisions also have the effect of ensuring against the risk of convicting an innocent person. See, e. g., Coy ...