A more thorough explanation:

A petit jury, also known as a traverse jury, is a group of people who are sworn in to determine the guilt or innocence of a defendant in a trial. Unlike grand juries, petit juries are responsible for trying the case itself and returning a verdict.

Petit juries are usually composed of twelve members, but can be no less than six. In the past, most states and federal courts required a unanimous decision from the jury, but this has been subject to debate. In some cases, a majority rule verdict may be sufficient to satisfy the beyond a reasonable doubt standard.

The right to a jury trial is protected by the sixth and seventh amendments, but a defendant may choose to waive this right and opt for a bench trial instead. However, in capital cases, a jury trial is mandatory.

In a criminal trial, a petit jury would be responsible for hearing the evidence presented by both the prosecution and defense, and then deciding whether the defendant is guilty or not guilty.

For example, if a person is accused of robbery, the petit jury would hear testimony from witnesses, examine physical evidence, and review any other relevant information before deciding whether the defendant is guilty beyond a reasonable doubt.

Another example would be a civil trial, where a petit jury would be responsible for deciding whether a defendant is liable for damages.

Overall, petit juries play a crucial role in the American legal system by ensuring that defendants receive a fair trial and that justice is served.