What Really Happens During a Grand Jury in Maricopa County

Despite what people might (understandably) assume from the name, a grand jury isn’t a special jury that only deals with big, important cases. It’s actually a panel of jurors whose only role is determining whether probable cause exists for felony charges to be brought against an individual.

In Arizona, a grand jury is one of two paths a prosecutor can use to establish probable cause for felony charges. The other path is a preliminary hearing. Cases typically go through one or the other, not both.

What is a grand jury in Maricopa County?

A grand jury is a panel of regular citizens selected from the same pools used for normal jury duty. Unlike a trial jury, this group serves for months at a time and may review many cases during their term.

They are only tasked with deciding whether the prosecutor has shown enough evidence to support probable cause. This threshold is much lower than the burden of proof used at trial, and the panel’s decision controls whether formal charges are filed through an indictment.

A state grand jury handles Arizona felony cases, while federal grand juries review offenses handled by U.S. prosecutors. The general structure is similar, but they operate under different rules and jurisdictions.

What happens inside the grand jury room?

The prosecutor controls the presentation. They decide which witnesses to call, what evidence to show, and what background information to give the panel. Prosecutors can present hearsay, summaries of investigative reports, and testimony from law enforcement officers.

If that sounds biased, it’s because it is. This is a process driven entirely by prosecutors. The grand jurors themselves are intended to be the safeguard against prosecutorial overreach.

Sessions are usually brief. A grand jury may hear several cases in a single meeting. After the presentation, the jurors deliberate privately and vote. Only a majority is needed to issue an indictment.

Can a defendant testify?

A defendant may ask to testify, or the prosecutor may invite them, but it is uncommon. Testifying carries risks because the prosecutor frames the questions, and the defendant cannot present full context or introduce competing evidence.

Are defense attorneys present?

Arizona law restricts who may be present in the grand jury room. The prosecutor, the jurors, witnesses, and a court reporter may attend. Defense attorneys cannot enter the room, cannot question witnesses, and cannot challenge how the evidence is presented.

If a defendant does testify before a grand jury, they may consult with their lawyer beforehand, and may step outside the room during questioning to ask for advice, but their defense lawyer cannot speak inside the proceeding.

Requests to clarify the law or present additional information must be made through limited procedural channels. In practice, there’s very little a defense attorney can do at this stage, which is why, when a grand jury is used, most defense strategies are only formulated after an indictment is issued.

What happens after an indictment?

Once the grand jury votes to indict, the prosecutor files formal charges. Depending on the situation, the defendant may receive a summons or have a warrant issued for their arrest. The next steps include an arraignment and the beginning of the formal court process.

How Grand Juries Differ From Preliminary Hearings

A preliminary hearing serves the same legal function as a grand jury, but they work very differently, and only one is used in a given case.

A preliminary hearing is a public court proceeding in front of a judge where the defense attorney can question witnesses and challenge the State’s evidence. The rules of evidence are stricter, and the judge decides whether the case moves forward.

Prosecutors frequently choose the grand jury because it deprives the alleged perpetrator of the adversarial safeguards of a preliminary hearing. There is no defense attorney questioning witnesses, no judge scrutinizing the evidence, and no real challenge to the State’s version of events during a grand jury.

Unfortunately, people under investigation for felonies don’t get a say in which process is used to decide their charges.

What the Average Arizonan Should Know About Grand Jury Duty

Can you actually get a notice for grand jury duty?

Yes. Arizona residents can receive a summons specifically for grand jury service, not just regular trial jury duty. The summons typically says something like “Grand Jury Panel Selection” and does not list a specific case because grand jurors review many cases during their term.

How are grand jurors selected?

Grand jurors are chosen from the same pool used for regular jury duty:

• Voter registration records
• Driver’s license and state id databases

If your name is pulled, you may be assigned to the grand jury panel instead of a trial courtroom.

Unlike a normal trial jury, there is no voir dire where opposing attorneys question potential jurors. Grand jury members are selected administratively by the court, not through challenges or strikes from either side.

After reporting for service, potential jurors are given basic orientation and screened only for statutory disqualifications or clear hardships, not for how they might evaluate a particular case.

Can you be excused from grand jury duty?

Courts are generally more flexible in excusing people from grand jury service because it lasts longer and creates a greater burden. Common reasons for excusal include:

• Work hardship
• Caregiver responsibilities
• Transportation issues
• Medical limitations
• Significant scheduling conflicts

If excused from grand jury service, you’re usually returned to the general jury pool.

Are you excused from future jury duty if you serve on a grand jury?

The exemption is longer for grand juries than it is for normal jury duty (which is only a two year exemption). If you serve on an Arizona or Maricopa County grand jury for more than two sessions, you’re exempted from future jury duty for four years. 

Are employers required to let you serve?

Yes. As with normal jury duty, Arizona law prohibits employers from firing or disciplining someone for completing grand jury service. Because grand jury terms are longer, courts often weigh employment hardship more heavily when deciding whether to excuse someone.

Do grand jurors hear evidence the public never sees?

Yes. Grand jury proceedings are confidential. Jurors may hear:

• Hearsay
• Early investigative evidence
• Witness statements
• Physical or digital evidence

This confidentiality is one of the biggest differences from a public preliminary hearing.

You Don’t Have to Wait for the Results of a Grand Jury or Preliminary Hearing Before Speaking With a Defense Attorney in Phoenix

Whether a defense attorney can help at the grand jury stage is highly dependent on the specifics of the allegations. It’s not uncommon for people suspected of white collar, drug crimes, or fraud cases to only learn about a grand jury after it has already approved charges. However, in-progress or immediate-response crimes can be a different matter.



If you suspect law enforcement is investigating you for a felony, you do not have to wait for charges to be filed to speak with a defense attorney. Contact Board-Certified Criminal Law Specialist Michael Alarid III at (602) 818-3110 for a free case evaluation.