A petit juror’s responsibility is to determine issues of fact “beyond a reasonable doubt” in civil and criminal cases and to reach a verdict in conjunction with those findings. A grand juror’s responsibility is to determine “probable cause” based on the facts and accusations presented by the prosecutor. If a grand jury finds probable cause, an indictment will be handed down. An indictment is the most common way a criminal case starts. In summary, grand jurors decide if there is enough evidence to indict (file charges) and petit jurors decide guilt or innocence.