When jurors report to the Maricopa County Superior Court South Court Tower in downtown Phoenix for the first time, most jurors picture themselves serving on a trial jury in a public courtroom to render a verdict in either a civil or criminal case, formally referred to as a “petit” jury. However, many are surprised to learn they’ve been summoned for grand jury service instead.

A grand jury is a group of people (16 jurors and approximately 10 alternates) who review evidence of alleged crimes presented by the prosecutor and determine if there is enough evidence for probable cause to formally charge someone with a crime. Grand jury proceedings are confidential to protect everyone involved and ensure a fair investigation. Confidentiality helps protect the reputations of individuals who are investigated but never charged. It also encourages witnesses to speak openly and honestly without fear of retaliation or public exposure.

While petit jurors use proof beyond a reasonable doubt in their decision-making process – grand jurors simply need to find that probable cause, a much lesser burden, exists for a case to be initiated.

“Jurors are more familiar with the petit jury process they see on TV shows,” Jury Administrator Tiana Burdick said.  “While petit jurors serve in public, grand jurors serve in private. Since the grand jury process takes place behind closed doors, it does not get the same public attention as a petit jury. Grand juries uphold due process guarantees set forth in the U.S. and Arizona Constitutions,” Burdick said.

In Arizona, there are two types of grand juries: county and state grand juries. County grand juries involve crimes brought forth by the Maricopa County Attorney’s Office or the Attorney General’s Office. State grand juries typically involve complex investigations like fraud schemes, public corruption or organized crime usually brought by the Attorney General’s Office. Both juries are summoned by the Judicial Branch Jury Office.

Commissioner Nicholas Saccone has presided over grand jury matters for over two years. Commissioner Saccone is one of the judicial officers responsible for overseeing grand jury selection, reviewing the appointment of alternate grand jurors and swearing in grand jurors.

“Grand juries safeguard the community by ensuring that probable cause exists before anyone is charged with a crime,” Commissioner Saccone said. “They give community members a direct role in the justice system - allowing everyday citizens to participate in important legal decisions that affect the public.”

During grand jury sessions, jurors can ask questions, discuss the evidence privately and vote on whether probable cause exists. Judges and attorneys do not participate in their deliberations.

The Clerk of Superior Court in Maricopa County also plays a significant role in the grand jury process - providing administrative and operational support.

“The Clerk's office works diligently behind the scenes to maintain the integrity of the judicial process and support the Court at every step," said Clerk of Court Operations Administrator Ana Namauleg. "Our team provides critical, highly confidential support to grand jury proceedings by ensuring every case is processed accurately, court records are properly initiated, and all required notices, warrants and documentation are handled efficiently."

Maricopa County Grand jurors are empaneled two to three times per month - meeting twice a week for four months. State grand jurors serve a term of six months and meet one to three times per week.

Last year, the Judicial Branch summoned more than 12,600 people to serve on Maricopa County grand jury panels. Approximately 930 grand juries have been convened in Maricopa County over the last 20 years.

To learn more about jury service, please visit: https://superiorcourt.maricopa.gov/jury/