A grand jury is a panel of citizens who review evidence in secret and decide whether the government has enough proof to formally charge someone with a serious crime. The Fifth Amendment requires one before anyone can be prosecuted for a serious federal offense, which makes it one of the oldest checks on prosecutorial power in American law.1Congress.gov. Fifth Amendment It does not decide guilt. It decides whether a case should move forward at all.
How a Grand Jury Differs From a Trial Jury
A trial jury (sometimes called a petit jury) hears both sides of a case in open court and decides whether the defendant is guilty beyond a reasonable doubt. A grand jury does something narrower and earlier. It listens to the prosecutor’s evidence, without a judge in the room and without the defense present, and votes on whether there is probable cause to believe a crime occurred and the person under investigation committed it.
Probable cause is a much lower bar than proof beyond a reasonable doubt. The grand jury is not deciding whether someone is guilty. It is deciding whether the evidence is strong enough to justify putting them through a prosecution. Cases that clear that bar move on to arraignment and trial. Cases that don’t, at least for the moment, stop.
Who Sits on a Grand Jury
Federal grand jurors come from the same pool as trial jurors. To qualify you must be a U.S. citizen, at least 18 years old, a resident of the judicial district for at least a year, and able to read, write, and speak English.2United States Courts. Juror Qualifications, Exemptions and Excuses The service commitment is much longer than a normal trial. Grand jurors serve up to 18 months, sometimes extended to 24, meeting anywhere from one day every other week to several days a week depending on the district’s caseload.3United States Courts. Types of Juries
A federal grand jury has between 16 and 23 members. State panels vary, and some states seat as few as 12. The court appoints a foreperson and a deputy from among the jurors. The foreperson swears in witnesses, signs indictments, and records how each vote came out.4Office of the Law Revision Counsel. Federal Rules of Criminal Procedure Rule 6
What Happens Inside the Room
Grand jury proceedings are closed. While a witness is testifying, only government attorneys, the witness, an interpreter if one is needed, and a court reporter may be present.4Office of the Law Revision Counsel. Federal Rules of Criminal Procedure Rule 6 The judge is not there. The witness’s lawyer is not there. When the jurors deliberate and vote, everyone else leaves.
Secrecy is required by law. Federal Rule 6(e) forbids jurors, court reporters, interpreters, and government attorneys from disclosing what happens.4Office of the Law Revision Counsel. Federal Rules of Criminal Procedure Rule 6 The point is to protect people who are investigated but never charged, encourage witnesses to speak honestly, and keep targets from tampering with evidence or fleeing.
Grand juries also have investigative powers that police on their own do not. They can issue two kinds of subpoenas. A subpoena duces tecum forces someone to turn over documents or physical evidence. A subpoena ad testificandum forces a person to appear and testify under oath.5United States Department of Justice. Justice Manual 9-11.000 – Grand Jury Ignoring a subpoena without legal justification can lead to civil contempt and confinement for as long as the grand jury sits, capped at 18 months.6Office of the Law Revision Counsel. 28 USC 1826
The rules of evidence are looser than at trial. Grand juries can consider hearsay, and the Supreme Court has held that an indictment based entirely on hearsay is still valid.7Justia. Costello v. United States, 350 U.S. 359 (1956)
What Rights a Witness Has
Being subpoenaed to a grand jury is unnerving, in part because your lawyer cannot go inside with you. Witnesses still have real protections.
The Fifth Amendment privilege against self-incrimination applies. You can refuse to answer any question when a truthful answer might be used against you in a criminal case. You do not have to be guilty of anything to invoke it. The grand jury can compel you to show up, but it cannot force you to incriminate yourself.
You have the right to counsel, just not in the room. You can pause and step outside to consult with your lawyer as often as you need to.5United States Department of Justice. Justice Manual 9-11.000 – Grand Jury Defense attorneys typically wait right outside the door for this reason.
If prosecutors need testimony from a witness who is asserting the Fifth, they can ask a court for an immunity order. Federal law grants “use immunity,” which means the government cannot use the compelled testimony, or evidence derived from it, against the witness in a criminal case.8Office of the Law Revision Counsel. 18 USC 6002 Once the order issues, the witness can no longer refuse on Fifth Amendment grounds. The government can still prosecute the underlying conduct if it builds the case from independent evidence.
The Justice Department also encourages prosecutors to send a “target letter” to the main person under investigation, alerting them and giving them a chance to testify voluntarily.5United States Department of Justice. Justice Manual 9-11.000 – Grand Jury It is not required, and prosecutors will skip it when notice would compromise the investigation.
The Two Possible Outcomes
When the grand jury believes probable cause exists, it returns a “true bill,” which is the indictment.5United States Department of Justice. Justice Manual 9-11.000 – Grand Jury In federal court at least 12 jurors must agree.4Office of the Law Revision Counsel. Federal Rules of Criminal Procedure Rule 6 The foreperson or deputy returns the indictment to a magistrate judge in open court, and the case moves to arraignment.
If fewer than 12 vote yes, the foreperson reports the lack of concurrence to the magistrate in writing. That result is called a “no bill.” A no bill stops the case for now, but it does not permanently protect the target. Double jeopardy does not attach at this stage, so a prosecutor can bring the same case to a different grand jury. Federal policy requires the U.S. Attorney’s approval before resubmitting, but there is no legal bar to trying again with more evidence.5United States Department of Justice. Justice Manual 9-11.000 – Grand Jury
Federal Requirement, State Discretion
The Fifth Amendment’s grand jury requirement applies only to federal prosecutions. The Supreme Court held in 1884 that states are not constitutionally required to use grand juries at all.9Justia. Hurtado v. California, 110 U.S. 516 (1884) Roughly half of states still require grand jury indictments for serious felonies. The rest let prosecutors file charges directly through a document called an “information,” which a judge reviews for probable cause. Some states with no grand jury requirement still use them for complex or politically sensitive investigations, because the subpoena power and secrecy are useful regardless of whether an indictment is technically required.
Waiving the Grand Jury
A federal felony defendant can give up the right to a grand jury indictment. Under Federal Rule of Criminal Procedure 7, the waiver must happen in open court after the defendant is advised of the charges and their rights.10Legal Information Institute. Federal Rules of Criminal Procedure Rule 7 The case then proceeds by information. Waivers are common in plea deals, where insisting on grand jury review would only slow down a resolution the defendant has already agreed to.
Special Grand Juries
For long or complex investigations, federal courts can empanel a special grand jury. These are convened in judicial districts with more than four million residents, or whenever the Attorney General certifies that significant criminal activity in the district calls for one.11Office of the Law Revision Counsel. 18 USC 3331 Their initial term is 18 months, extendable in six-month increments up to a total of 36 months. They tend to handle the cases regular grand juries lack time for: organized crime, public corruption, and large-scale financial fraud.