Herrera v. Collins
United States Supreme Court
506 U.S. 390 (1993)
Leonel Torres Herrera (defendant) was convicted of one murder and pled guilty to another, with his conviction and death sentence upheld on direct appeal and through failed state and federal habeas petitions. Ten years after his conviction, Herrera sought state relief claiming "actual innocence" based on new evidence that his brother committed the crimes; after the state court denied that claim, he filed a federal habeas petition, this time alleging the state had withheld exculpatory evidence in violation of Brady v. Maryland.
Whether federal habeas corpus relief for a claim of actual innocence is available when no independent constitutional violation occurred during the underlying state criminal proceedings.