A petit jury, sometimes called a traverse jury, is a body that is sworn in to try the facts of the case. Petit juries are juries known in the common sense; they are responsible for determining the guilt of the defendant and returning a verdict, but they serve a different function than grand juries. Grand juries are not responsible for trying a case itself, rather, they serve to determine whether there is probable cause to indict a potential defendant.
A petit jury is usually composed of twelve members and can be no less than six. Though, traditionally, most states and all federal courts required that a jury's decision be unanimous, this requirement has been subject to debate. In Apodaca v. Oregon and Johnson v. Louisiana, two Supreme Court cases decided on the same day, the Court held that majority rule verdicts do not violate the due process and equal protection clauses of the Fourteenth Amendment. Specifically, the Court found that verdicts supported by a large majority (ten to two in Apodaca and nine to three in Johnson) were sufficient to satisfy the beyond a reasonable doubt standard.
This holding was eventually overruled in Ramos v. Louisiana, where the Supreme Court held that a unanimous verdict was required to convict a defendant of any serious offense in all states.
The right to a jury trial is protected by the sixth and seventh amendments. However, a criminal defendant is usually allowed to waive this right and opt for a bench trial, with the exception of capital cases.
[Last updated in July of 2020 by the Wex Definitions Team]