Edward George McGregor v. Texas

Napue v. Illinois, 360 U.S. 264 (1959), held that a conviction violates due process when it is based on false, material testimony that the prosecution knowingly elicited or failed to correct. False testimony is material unless the prosecution proves beyond a reasonable doubt that it did not contribute to the conviction. Lower courts are divided on the standard for determining the materiality of false testimony. Most have held that materiality is determined by considering the effect on the verdict had the jury known that the witness lied and the prosecutor was complicit. The Texas Court of Criminal Appeals (TCCA), following the minority approach, concluded that false testimony that two witnesses did not have agreements with the prosecution was immaterial because it did not refute the substance of their testimony that petitioner had confessed to them and the prosecution’s case was “fairly strong.” It ignored the time-honored legal maxim that cross-examination demonstrating that a witness has lied about one matter undermines not only his credibility but also the substance of his testimony. The question presented is: Is the materiality of false testimony knowingly used by the prosecution determined by asking whether the jury would have convicted the defendant had the witnesses told the truth or by asking whether the jury would have convicted him had he been able to impeach them on cross-examination?