Grand Jury Guide: How Grand Juries Work in Criminal Cases
Before most federal felony defendants ever see a courtroom, they must survive a secret proceeding that determines whether they will be charged at all. The grand jury is one of the least understood institutions in American criminal law. Operating behind closed doors, hearing only the prosecution’s evidence, and applying a standard far lower than reasonable doubt, the grand jury has been described as both a vital check on prosecutorial power and a rubber stamp for whatever charges the government wants to bring.
The grand jury is rooted in English common law and was considered so important by the framers that they included it in the Fifth Amendment: “No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury.” Understanding how grand juries work is essential for understanding how the federal criminal justice system actually operates.
The Role of the Grand Jury
The grand jury serves two functions. Its primary function is to determine whether probable cause exists to believe that a crime has been committed and that a specific person committed it. If the grand jury finds probable cause, it issues an indictment — a formal charging document that authorizes the prosecution to proceed.
The grand jury also serves an investigative function. It can issue subpoenas for documents and testimony, compelling witnesses to appear and answer questions under oath. This investigative power allows the grand jury to gather evidence before any charges are filed and to build the case that the prosecutor will eventually present.
Federal grand juries consist of 16 to 23 citizens. A quorum of at least 12 members must be present, and at least 12 must vote to indict. The grand jury is impaneled for a term of up to 18 months for a regular grand jury or up to 36 months for special grand juries, though these terms can be extended.
Grand Jury vs. Trial Jury
The grand jury is fundamentally different from the trial jury in almost every respect. A trial jury decides guilt or innocence after hearing evidence from both sides. A grand jury decides whether there is enough evidence to charge someone. A trial jury must be unanimous. A grand jury needs only a majority. A trial jury hears evidence presented by both the prosecution and the defense. A grand jury hears only the prosecution’s evidence. The defense has no right to present evidence, cross-examine witnesses, or even be present.
The standard of proof is also dramatically different. A trial jury must find the defendant guilty beyond a reasonable doubt. A grand jury need only find probable cause — a far lower standard that requires only a reasonable belief that the defendant committed the crime.
Secrecy of Grand Jury Proceedings
Grand jury proceedings are conducted in secret. Only the prosecutor, the grand jurors, and the witness being questioned are present. The judge is not in the room. No court reporter is required, though many jurisdictions record the proceedings. Transcripts are generally sealed and cannot be disclosed except in limited circumstances.
The secrecy serves several purposes. It encourages witnesses to testify freely without fear of retaliation. It prevents potential defendants from fleeing before charges are filed. It protects the reputation of people who are investigated but not indicted. And it prevents suspects from learning the details of the investigation and destroying evidence or influencing witnesses.
Secrecy and the Defense
The secrecy of grand jury proceedings creates a significant asymmetry. The defense has no right to learn what happened in the grand jury room unless the government introduces grand jury testimony at trial. This means that the defense may never know whether the grand jury heard exculpatory evidence, whether witnesses contradicted each other, or whether the prosecutor presented a balanced picture.
The criminal defense strategies guide explains how defense attorneys use the limited discovery available to reconstruct what happened in the grand jury and identify potential grounds for challenging the indictment.
The Prosecutor and the Grand Jury
The prosecutor plays a dominant role in grand jury proceedings. It is the prosecutor who decides which witnesses to call, what documents to present, and how to frame the evidence. The prosecutor advises the grand jury on the law and may even draft the indictment that the grand jury votes on.
The grand jury has the power to refuse to indict — known as a no bill — but this is rare. As former New York Court of Appeals Chief Judge Sol Wachtler famously observed, a grand jury would “indict a ham sandwich” if a prosecutor asked it to. Empirical research supports this observation: federal grand juries indict in over 99 percent of cases presented to them.
Grand Jury Abuse
The imbalance of power in grand jury proceedings has led to concerns about abuse. Prosecutors may present evidence that would be inadmissible at trial, such as hearsay or illegally obtained evidence. They may call witnesses who will invoke their Fifth Amendment privilege in front of the grand jury, creating an inference of guilt. They may selectively present only the evidence that supports an indictment.
Some states have attempted to reform grand jury abuse. A few states require the prosecutor to present exculpatory evidence to the grand jury. Others have abolished the grand jury entirely, allowing prosecutors to file charges directly through a complaint and preliminary hearing process.
The Grand Jury Subpoena
One of the grand jury’s most powerful tools is the subpoena. A grand jury subpoena can compel a witness to appear, testify under oath, and produce documents. Unlike a search warrant, a subpoena does not require probable cause. It need only seek information that is relevant to the grand jury’s investigation and not overly broad.
Failure to comply with a grand jury subpoena can result in contempt of court and incarceration. The subpoena power extends to documents held by third parties, including banks, employers, and business partners. Unlike trial subpoenas, grand jury subpoenas are not subject to immediate challenge by the target of the investigation.
Witness Rights Before the Grand Jury
Witnesses before the grand jury have limited rights. A witness may refuse to answer questions that would incriminate them, invoking the Fifth Amendment privilege. However, the prosecutor may grant immunity — either transactional immunity (protecting from prosecution for the offense) or use immunity (protecting only against the use of the compelled testimony) — and then compel the witness to testify.
The target of the investigation — the person who may be indicted — has no right to testify before the grand jury unless the prosecutor permits it. Most prosecutors do not extend this invitation because it gives the target an opportunity to hear the evidence and tailor their story. The evidence law guide explains how grand jury testimony may be used at trial.
The Target’s Rights
The target of a grand jury investigation — the person who may be indicted — has limited rights but some important protections. The target generally must be notified that they are the target of the investigation and may be given an opportunity to testify, though most defense attorneys advise targets to refuse this invitation.
The prosecutor must instruct the grand jury on the law accurately. If the prosecutor gives incorrect legal instructions or withholds exculpatory evidence, the target may move to dismiss the indictment. The criminal defense strategies guide explains how defense attorneys challenge defective indictments.
State Grand Juries
The Fifth Amendment’s grand jury requirement applies only to federal prosecutions. The Supreme Court held in Hurtado v. California (1884) that the grand jury requirement does not apply to the states through the Fourteenth Amendment. As a result, states handle felony charging differently.
Approximately half of the states use grand juries for some or all felony charges. The others use preliminary hearings, where a judge hears evidence and determines whether probable cause exists. Some states use a hybrid system, allowing the prosecutor to choose between a grand jury and a preliminary hearing.
Frequently Asked Questions
Can you refuse to testify before a grand jury? You can invoke your Fifth Amendment privilege against self-incrimination, but if you are granted immunity, you must testify or face contempt. There is no general right to refuse a grand jury subpoena.
Do you need a lawyer for grand jury? You have the right to consult with a lawyer, but your lawyer cannot be in the grand jury room with you. You may step outside to consult with your lawyer between questions in some jurisdictions.
What happens if the grand jury indicts? The case proceeds to arraignment in open court. The indictment becomes a public document, and the defendant is formally notified of the charges.
Can a grand jury indictment be challenged? Yes. The defendant may file a motion to dismiss the indictment based on defects in the grand jury process, such as prosecutorial misconduct, improper evidence, or insufficient evidence.
Is the grand jury required for all federal crimes? The Fifth Amendment requires a grand jury for all capital and infamous crimes — felonies. Misdemeanors do not require a grand jury indictment and may be charged by information filed directly by the prosecutor.
Criminal Procedure Overview — Beyond a Reasonable Doubt — Evidence Law Guide