Napue v. Illinois
The Court held that a prosecutor's knowing use of false testimony in a criminal case violates the Due Process Clause of the Fourteenth Amendment, even if it affects only the witness's credibility and not the defendant's guilt or innocence.· AI-written
360 U.S. 264 · No. 583 · 1958 term · Warren Court
Decided Jun 15, 1959 · argued Apr 30, 1959
Criminal procedure · Extra-legal jury influences: prejudicial statements or evidence
Majority opinion: Earl Warren
The voteMajority
9–09 in the majority, 0 in dissent
No dissent (9–0)
Reversed. Napue won.
What this ruling means
Reversed: the Supreme Court overturned the decision of the Illinois Supreme Court, and its own ruling ends the case.
Napue was the petitioner, the side that asked the Supreme Court to review the case. “Won” means the Court gave that side the result it asked for.
From the Supreme Court Database. A justice who agreed with the result but not the reasoning counts in the majority.
Summary
The opening of the case’s Wikipedia article: what the case was about and what the Court held.
Napue v. Illinois, 360 U.S. 264 (1959), was a United States Supreme Court case in which the Court held that the knowing use of false testimony by a prosecutor in a criminal case violates the Due Process Clause of the Fourteenth Amendment to the United States Constitution, even if the testimony affects only the credibility of the witness and does not directly relate to the innocence or guilt of the defendant.
Data notes
The text is Wikipedia’s (CC BY-SA 4.0), matched to the case by its citation, docket number or name and year, and is not checked against the opinion. The site keeps the article’s opening section, ending on its last full sentence. The one-sentence summary under the title is the Decisions list’s: Wikipedia’s own ruling sentence, or, tagged “AI-written”, one Claude wrote from this opening.
How the justices voted
Each justice who took part, placed by their Martin–Quinn ideology score for the 1958 term. Filled: the 9 in the majority. Hollow: the 0 in dissent. Colour is the party of the president who appointed them.
Majority(9)
Earl WarrenWrote the majority opinion
William DouglasJoined the majority
Hugo BlackJoined the majority
William BrennanJoined the majority
Tom ClarkJoined the majority
Potter StewartJoined the majority
Charles WhittakerJoined the majority
John HarlanJoined the majority
Felix FrankfurterJoined the majority
Dissent(0)
- None.
Data notes
Each justice’s vote and what they wrote are from the justice-centered file of the Supreme Court Database. “Wrote a concurrence” means the justice sided with the majority and wrote separately; a justice who dissented in part is counted on the side they took overall. A justice who wrote nothing is listed as joining their side.
Positions are each justice’s Martin–Quinn score for the case’s term, the same scores as the Ideology page: negative is more liberal, positive more conservative. A score sums up a justice’s votes across the whole term, so it says where they usually sit, not why they voted as they did here. The median line is the Court’s median justice that term.
The parties
Who brought the case to the Court, who answered it, and how it got there.
- Petitioner
- NapuePerson accused, indicted, or suspected of crime
- Respondent
- IllinoisState (Illinois)
- Reached the Court by
- Certiorari (the Court chose to hear it)
Data notes
The names are the two sides of the case’s title. The description under each is the Supreme Court Database’s category for that party, in its own wording. The petitioner is the side that asked the Supreme Court to review the decision below. “Why it was taken” appears only when the majority opinion says lower courts disagreed or were unsure about the question; reasons that would fit any case (“to resolve the question presented”, “an important question”) are left out.
The law at issue
The law the Court was asked to apply, and the kind of power it used to decide.
- Provision
- Fourteenth Amendment (due process)
- Kind of law
- Constitutional Amendment
- Decided by
- Judicial review (state level)
Data notes
The Supreme Court Database codes the main constitutional provision, statute or court rule each case turned on, and the basis of the decision: judicial review of a federal or state law, interpreting a statute, supervising the lower courts, and so on. A case can rest on more than one. “Overruled” counts only where the majority opinion says so.
Timeline
What happened at the Court and how the case got there, newest first.
- Jun 15, 1959DecidedDecided · Decided 9–0: reversed. Napue won.
- Apr 30, 1959ArguedArgued · Oral argument before the Court.
- Not datedTaken upTaken up · The Supreme Court agreed to hear the case (certiorari).
- Not datedCourt belowCourt below · Decided by the Illinois Supreme Court: affirmed, with a dissent.
- Not datedBeganBegan · The case began in the Illinois trial court.
Data notes
From the Supreme Court Database: the court the case began in, the court whose decision the Supreme Court reviewed and what that court did, how the case came to the Court, and the dates of argument and decision. The database does not date the steps in the lower courts. Court names are the database’s.
Other decisions on the same issue
9 other argued cases since 1946 on extra-legal jury influences: prejudicial statements or evidence, newest first.
- Pena-Rodriguez v. Colorado137 S. Ct. 855Mar 6, 2017 · 137 S. Ct. 855Criminal procedure5–36–3 band
- Donnelly v. Dechristoforo416 U.S. 637May 13, 1974 · 416 U.S. 637Criminal procedure6–36–3 band
- Loper v. Beto, Corrections Director, et al.405 U.S. 473Mar 22, 1972 · 405 U.S. 473Criminal procedure5–45–4 band
- Giles et al. v. Maryland386 U.S. 66Feb 20, 1967 · 386 U.S. 66Criminal procedure5–45–4 band
- Miller v. Pate, Warden386 U.S. 1Feb 13, 1967 · 386 U.S. 1Criminal procedure9–0Unanimous band
- Alcorta v. Texas355 U.S. 28Nov 12, 1957 · 355 U.S. 28Criminal procedure9–0Unanimous band
- Delli Paoli v. United States352 U.S. 232Jan 14, 1957 · 352 U.S. 232Criminal procedure5–45–4 band
- United States ex rel. Darcy v. Handy, Warden, et al.351 U.S. 454Jun 11, 1956 · 351 U.S. 454Criminal procedure6–36–3 band
- Costello v. United States350 U.S. 359Mar 5, 1956 · 350 U.S. 359Criminal procedure7–0Unanimous band
Data notes
Every other orally argued case with a clear vote, from the 1946 term on, that the Supreme Court Database files under the same issue as this one. The database gives each case one issue from a list of about 270 (abortion, search and seizure of vehicles, the death penalty, and so on), whatever law it turned on.
Official record
Read the full opinion on Justia, the argument audio on Oyez and Wikipedia. Case data from the Supreme Court Database, Version 2026 Release 01, through the 2025 term.