Trial by Jury

• Description: A legal process in which a group of citizens sworn as jurors hear evidence presented at trial and collectively decide on the accused’s culpability for crimes or civil offenses.
• Relevant amendments: Sixth, Seventh

Significance: Supreme Court rulings affirm the importance of trial by jury as a protection against government oppression of the accused and as an avenue for citizen participation in the democratic process.

Article III, Section 2, of the US Constitution provides the right to trial by jury for all crimes except impeachment. The Seventh Amendment grants this right in civil cases involving twenty dollars or more. The Sixth Amendment provides the right to be tried by an impartial jury.

In Palko v. Connecticut (1937), the Supreme Court interpreted these constitutional provisions as only applicable in federal trials, reasoning that trial by jury was not a fundamental right and therefore was not applicable to the states through the Fourteenth Amendment’s due process clause. This meant states were not required to provide jury trials but could choose to do so.

The Court reversed its position in Duncan v. Louisiana (1968)—ruling that trial by jury in criminal cases is a fundamental right applicable to the states. The Court’s reasoning in Duncan emphasized the importance of jury trials as part of due process and a significant aspect of participatory democracy. In subsequent cases, the Court clarified the scope of the right to trial by jury, finding it applicable in any case involving a minimum possible sentence of six months of incarceration and in some cases with a shorter penalty. However, the Court did not extend the Seventh Amendment requirement of trial by jury in civil cases to the states, instead leaving state governments to decide this.

Despite the Court’s recognition of the importance of trial by jury, minors in the juvenile justice system lack this right. The Court, in the case In re Gault (1967), reasoned that because juvenile court proceedings are not adversarial—in contrast to adult courts—jury trials are not necessary. However, juveniles tried in adult court gain the right to trial by jury.

Historically, jurors had the right to decide questions of both law and fact. However, in Sparf and Hansen v. United States (1899), the Court restricted jurors to deciding issues of fact. In their capacity as fact finders, jurors in criminal trials decide whether the prosecution has proven beyond a reasonable doubt that the defendant is guilty as charged—a requirement the Court noted in In re Winship (1970) that is intended to protect against erroneous convictions. Jurors in most civil cases use the less stringent “preponderance of the evidence” standard. In Witherspoon v. Illinois (1968), the Court emphasized the role of jurors as the conscience of the community.

In a 2018 case—McCoy v. Louisiana—defendant Robert McCoy was charged with murdering his wife and two other members of her immediate family. McCoy denied his guilt and—in testifying in his own defense—claimed to have been out of the state at the time of the murders. McCoy then blamed law enforcement officials for the killings. In an effort to spare McCoy from the death penalty, his lawyer acknowledged McCoy's guilt to the jury and suggested that McCoy's mental condition had prompted him to commit the acts. Jury members nonetheless returned a conviction and three death verdicts, which the Louisiana Supreme Court later upheld. In May 2018, the US Supreme Court overturned the decision. It reasoned that McCoy's Sixth Amendment rights had been violated because—despite his mental state—he retained the right to formulate the basis of his own legal defense.

In January 2024—in Smith v. Arizona—the Supreme Court heard arguments on the validity of testimony used to convict defendant Jason Smith. During Smith's original trial, a lab analyst had provided forensic testimony on behalf of prosecutors; however, the analyst had not conducted the original tests. Smith's lawyers argued that because a different person had testified, this action violated Jason Smith's Sixth Amendment right to confront his accusers. In June 2024, the Supreme Court ruled in favor of Smith and remanded the case to the state court.

Bibliography

Abramson, Jeffrey. We, the Jury. Basic Books, 1994.

Finkel, Norman J. Commonsense Justice: Jurors’ Notions of the Law. Harvard UP, 1995.

Howe Amy. "Court Appears to Favor Arizona Man’s Confrontation Clause Claim." SCOTUSblog, 10 Jan. 2024, www.scotusblog.com/2024/01/court-appears-to-favor-arizona-mans-confrontation-clause-claim. Accessed 8 Dec. 2025.

Kalven, Harry, Jr., and Hans Zeisel. The American Jury. U of Chicago P, 1970.

Litan, Robert E., editor. Verdict: Assessing the Civil Jury System. Brookings Institution, 1993.

"McCoy v. Louisiana." Oyez, www.oyez.org/cases/2017/16-8255. Accessed 8 Dec. 2025.

"Right to Trial by Jury: Scope of the Right." Cornell Law School, www.law.cornell.edu/constitution-conan/amendment-6/right-to-trial-by-jury-scope-of-the-right. Accessed 8 Dec. 2025.

"Trial by Jury." American Bar Association, www.americanbar.org/groups/criminal_justice/resources/standards/trial-by-jury. Accessed 8 Dec. 2025.

"Types of Juries." US Courts, www.uscourts.gov/court-programs/jury-service/types-juries. Accessed 8 Dec. 2025.