There are 2 ways in which a prosecutor can initiate criminal charges. Both involve presenting evidence that shows likelihood that the accused is guilty. One of these ways is through a grand jury.

A grand jury is a group of people, ranging from 11 to 23, who hear evidence against a defendant and decide if the case should proceed to trial. Their responsibility is not to determine if the defendant is guilty or innocent, but to decide if there are enough facts to support a charge against the defendant.

Who Can Be a Grand Juror?
A grand jury is a group of qualified people who are citizens of the county where the case is being tried. To qualify as a grand juror, a person must be:

• A citizen of the United States
• At least 18 years old
• A resident of the county for at least one year before being selected
• Of ordinary intelligence
• In possession of his or her natural faculties
• Of sound judgment and fair character
• English speaking
• Not serving as a trial juror or a public officer

Grand jurists are pre-selected before the beginning of the fiscal year by a jury commissioner and are selected from areas of the county in proportion to their population.

Role of the Grand Jury
Grand juries are used in lieu of holding a preliminary hearing for the defendant. The prosecutor (usually a district attorney) presents evidence and witnesses before the jury and attempts to make out a skeleton case for the charged offenses.

If the grand jury finds that the evidence, if uncontradicted, would warrant a conviction by a trial jury, they “indict,” or bring formal charges against, the defendant.

The Controversy of Grand Juries
Grand juries have come under fire from commentators because many people believe that the grand jury is biased: only the prosecutor is allowed to present evidence, and the jury must assume that the evidence is true.

Additionally, grand juries do not have to follow standard rules of evidence as trial juries do. For example, a grand jury is allowed to base their indictment on a police officer relating hearsay. In addition, some types of inadmissible evidence will not invalidate the indictment.