United States v. Lofton
In United States v. Lofton, 233 F.3d 313 (4th Cir. 2000), the U.S. Court of Appeals for the Fourth Circuit held that a new trial must be granted if false, material and surprising testimony was used to convict and the jury might have reached a different conclusion. See id. at 318.
The Court cited longstanding precedent in its jurisdiction that its courts do not tolerate perjury, and defendants ambushed by it need not prove innocence to obtain a new trial. See, e.g., United States v. Wallace, 528 F.2d 863, 866 (4th Cir. 1976) (rejecting any relaxation of the traditional Larrison rule).
Most Circuits affirm convictions now even if based on perjury.