How does a grand jury work?
What Is a Grand Jury?
A grand jury is a group of citizens empaneled by a court to review evidence presented by a prosecutor and determine whether there is enough probable cause to formally charge someone with a crime. Unlike a trial jury that decides guilt or innocence, a grand jury only decides whether criminal charges, known as an indictment, should be brought against a person. The process is rooted in the Fifth Amendment of the U.S. Constitution, which requires a grand jury indictment for federal felony charges.
| Feature | Details |
|---|---|
| Purpose | Determine whether probable cause exists to charge someone with a crime |
| Size | 16 to 23 members (federal); varies by state |
| Standard of proof | Probable cause (not beyond a reasonable doubt) |
| Constitutional basis | Fifth Amendment to the U.S. Constitution |
| Outcome | Indictment (true bill) or no indictment (no bill) |
| Proceedings | Conducted in secret; closed to the public |
Grand juries serve as a critical check on prosecutorial power. They act as a buffer between the government and individuals, ensuring that prosecutors cannot bring serious criminal charges without independent citizen review. This safeguard has existed in American law since the nation's founding and remains a cornerstone of the federal criminal justice system.
Purpose of a Grand Jury
The grand jury serves two primary functions: investigating potential criminal conduct and deciding whether to issue formal charges. It acts as a shield for citizens against unfounded or politically motivated prosecutions, while also serving as a sword that enables prosecutors to compel testimony and gather evidence through subpoena power.
| Function | Description |
|---|---|
| Screening function | Reviews evidence to decide if charges are warranted |
| Investigative function | Subpoenas documents, compels testimony, and gathers evidence |
| Protective function | Shields individuals from baseless or malicious prosecution |
| Oversight function | Can investigate government misconduct and issue reports |
Screening Charges
The most common role of a grand jury is reviewing evidence that a prosecutor has already gathered. The prosecutor presents witness testimony, documents, and other evidence. Grand jurors then vote on whether the evidence establishes probable cause that a specific person committed a specific crime. If a majority agrees, the grand jury issues an indictment.
Investigating Criminal Activity
Grand juries also have broad investigative powers. They can issue subpoenas to compel individuals to testify under oath, and they can require the production of documents, financial records, electronic communications, and other evidence. This investigative role is especially important in complex cases such as organized crime, public corruption, and financial fraud, where evidence may not be readily available to law enforcement.
Who Serves on a Grand Jury
A federal grand jury consists of 16 to 23 citizens drawn from the judicial district where the court sits. Grand jurors are selected through the same random process used for trial juries, typically from voter registration lists, driver's license databases, or other public records. To issue an indictment in federal court, at least 12 grand jurors must vote in favor of the charges.
| Aspect | Federal Grand Jury | State Grand Jury (Varies) |
|---|---|---|
| Number of jurors | 16 to 23 | Typically 12 to 23 |
| Votes required for indictment | At least 12 | Varies (often a simple majority or supermajority) |
| Term of service | Up to 18 months (can be extended to 24) | Varies by jurisdiction |
| Selection method | Random selection from the community | Random selection; some states use judicial appointment |
| Compensation | $50 per day | Varies (e.g., $15 per day in some California counties) |
Qualifications and Requirements
To serve on a grand jury, a person must generally be a U.S. citizen, at least 18 years old, a resident of the judicial district, and able to understand English. Individuals with felony convictions are typically disqualified. Grand jurors must also be physically and mentally capable of performing the duties required.
Unlike trial jury duty, which may last only a few days, grand jury service is a significant time commitment. Federal grand jurors may serve for up to 18 months, with sessions typically held one to three days per week. Some state grand juries have shorter terms, such as a maximum of six indictment hearings or one fiscal year.
The Grand Jury Foreperson
The court appoints one grand juror as the foreperson. This person presides over the proceedings, administers oaths to witnesses, and signs all indictments returned by the grand jury. The foreperson also keeps records of the number of jurors concurring in each indictment and reports this information to the court.
How Grand Jury Proceedings Work
Grand jury proceedings follow a structured but prosecutor-driven process. The prosecutor presents evidence, calls witnesses, and explains the relevant law. Grand jurors listen, ask questions, and ultimately vote on whether to issue an indictment. The entire process is conducted in secret, and the accused has no right to be present or to present a defense.
| Step | Description |
|---|---|
| 1. Empanelment | Grand jurors are selected and sworn in by the court |
| 2. Instruction | The judge instructs jurors on their duties and the law |
| 3. Presentation of evidence | The prosecutor presents witness testimony, documents, and other evidence |
| 4. Questioning | Grand jurors may ask witnesses questions |
| 5. Legal instruction | The prosecutor explains the specific charges and legal standards |
| 6. Deliberation | Grand jurors deliberate privately without the prosecutor present |
| 7. Vote | Jurors vote on whether to issue an indictment |
| 8. Return of indictment | If sufficient votes are reached, the indictment is filed with the court |
Presentation of Evidence
The prosecutor controls the flow of evidence presented to the grand jury. This typically includes calling witnesses who testify under oath, presenting physical evidence, introducing documents and records, and playing recordings or surveillance footage. Witnesses who appear before the grand jury may include law enforcement officers, victims, forensic experts, and other individuals with relevant knowledge.
Only a limited number of people may be present during grand jury sessions. Those allowed include the prosecutor, the witness currently testifying, a court reporter, an interpreter (if needed), and the grand jurors themselves. Defense attorneys, the accused, and members of the public are excluded.
Deliberation and Voting
After all evidence has been presented, the grand jury deliberates in complete privacy. No one other than the grand jurors may be present during deliberations. This is one of the most distinctive features of the process. Jurors discuss the evidence, consider the legal instructions provided by the prosecutor, and vote on whether probable cause exists.
In federal court, at least 12 of the 16 to 23 grand jurors must vote in favor of an indictment for it to be issued. State requirements vary. For example, in California, at least 12 jurors must vote for an indictment when 19 grand jurors are empaneled.
Evidence Rules in a Grand Jury
Grand jury proceedings operate under far more relaxed evidentiary rules than a trial. Hearsay evidence, which is generally inadmissible at trial, can be presented to a grand jury. There is no judge presiding over the proceedings to rule on objections, and the rules of evidence that govern courtroom trials largely do not apply.
| Evidence Rule | Grand Jury | Trial |
|---|---|---|
| Hearsay | Admissible | Generally inadmissible |
| Illegally obtained evidence | May be considered | Subject to exclusionary rule |
| Judge present | No | Yes |
| Cross-examination | Not permitted | Guaranteed right |
| Defense evidence | Typically not presented | Presented by defense counsel |
This relaxed approach means prosecutors have broad latitude in what they present. They are not required to present exculpatory evidence (evidence favorable to the accused) in most federal cases, although some states impose this obligation. Critics argue this imbalance gives prosecutors enormous influence over the outcome, while supporters contend it is appropriate for a preliminary screening process.
An indictment is not a finding of guilt. It is an accusatory pleading based on a standard of probable cause, sometimes described as "strong suspicion." A much higher standard of proof, beyond a reasonable doubt, is required for conviction at trial.
Possible Outcomes
After reviewing the evidence and deliberating, a grand jury reaches one of two main decisions: it either returns an indictment (a "true bill") or declines to indict (a "no bill"). The grand jury may also issue a presentment or a report in certain circumstances.
| Outcome | Meaning |
|---|---|
| True bill (indictment) | The grand jury finds probable cause and formally charges the accused |
| No bill (no indictment) | The grand jury finds insufficient evidence; no charges are filed |
| Presentment | The grand jury reports on misconduct discovered during its investigation (rare in modern practice) |
| Report | Some grand juries, particularly civil grand juries, issue public reports on government operations |
What Happens After an Indictment
If a grand jury returns a true bill, the indictment is filed with the court, and the accused is formally charged. The defendant is then arraigned, meaning they appear in court to hear the charges and enter a plea. From that point, the case proceeds through the normal criminal trial process, including pretrial motions, discovery, and ultimately a trial or plea negotiation.
The defendant retains the right to a jury trial before a separate trial (petit) jury, where the prosecution must prove guilt beyond a reasonable doubt. An indictment, by itself, carries no presumption of guilt.
What Happens With No Indictment
If the grand jury returns a no bill, the prosecutor may choose to present the case again to the same or a different grand jury, since double jeopardy protections do not apply at this stage. The prosecutor may also decide to pursue charges through a preliminary hearing before a judge, depending on the jurisdiction's rules. In some cases, the prosecutor may simply drop the matter entirely.
Grand Jury vs. Trial Jury
Grand juries and trial juries (also called petit juries) serve fundamentally different roles in the justice system. A grand jury determines whether charges should be filed, while a trial jury determines whether the accused is guilty. Nearly every aspect of the two proceedings differs, from the number of jurors to the standard of proof to the level of secrecy involved.
| Feature | Grand Jury | Trial Jury (Petit Jury) |
|---|---|---|
| Purpose | Decides whether to bring charges | Decides guilt or innocence |
| Size | 16 to 23 (federal) | 6 to 12 |
| Standard of proof | Probable cause | Beyond a reasonable doubt |
| Proceedings | Secret; closed to public | Open to the public |
| Defense attorney present | No | Yes |
| Defendant present | Generally no | Yes |
| Judge present | No (except for empanelment) | Yes, presides over the trial |
| Cross-examination | Not allowed | Fundamental right |
| Decision | Indictment or no indictment | Verdict of guilty or not guilty |
| Verdict requirement | Majority (e.g., 12 of 23) | Unanimous in federal cases |
| Term of service | Months (up to 18 months federal) | Days to weeks typically |
One of the starkest differences is the adversarial nature of proceedings. A trial is a contest between prosecution and defense, with a judge serving as referee. A grand jury hearing is not adversarial. Only the prosecution presents its case, and the accused has no opportunity to challenge evidence, cross-examine witnesses, or present a defense.
Rights of Witnesses and the Accused
The rights of individuals involved in grand jury proceedings are notably more limited than those available at trial. The accused typically has no right to appear, present evidence, or even know that a grand jury is investigating them. Witnesses, however, do retain certain constitutional protections.
| Right | Witnesses | The Accused |
|---|---|---|
| Right to an attorney in the room | No (attorney may wait outside) | Not present; N/A |
| Fifth Amendment privilege | Yes; may refuse to self-incriminate | Yes, if called to testify |
| Right to cross-examine | No | No |
| Right to present evidence | No | No (in most jurisdictions) |
| Right to know about investigation | Only if subpoenaed | Generally no |
Fifth Amendment Protections
Witnesses called before a grand jury have the right to invoke the Fifth Amendment and refuse to answer questions that might incriminate them. However, a prosecutor can overcome this privilege by granting the witness immunity. Once immunity is granted, the witness must testify or face contempt of court charges, which can result in incarceration. For more on the constitutional protections involved, see our guide on Miranda rights and the Fifth Amendment.
There are two types of immunity a prosecutor can offer. Transactional immunity protects the witness from prosecution for any crime related to their testimony. Use immunity, which is more common, only prevents the prosecution from using the witness's specific testimony against them, while still allowing charges based on independently obtained evidence.
Right to Counsel
Witnesses appearing before a grand jury do not have the right to have an attorney present in the grand jury room. However, they may consult with their attorney outside the room. In practice, a witness may leave the grand jury room to speak with their lawyer before answering questions, though this can slow proceedings considerably.
Federal vs. State Grand Juries
The Fifth Amendment requires grand jury indictments for federal felony cases, but this requirement has not been incorporated against the states through the Fourteenth Amendment. As a result, each state is free to decide whether and how to use grand juries. This has led to significant variation across the country.
| Jurisdiction | Grand Jury Requirement |
|---|---|
| Federal courts | Required for all felonies (Fifth Amendment) |
| Approximately half of U.S. states | Require grand jury indictment for some or all felonies |
| Remaining states | Allow prosecutors to file charges through a preliminary hearing or information |
| Connecticut and Pennsylvania | Have largely abolished the grand jury for routine criminal cases |
States that do not require grand jury indictments typically allow prosecutors to file charges through a document called an "information." Before an information can be filed, the accused usually has the right to a preliminary hearing before a judge, who determines whether probable cause exists. This process provides a judicial check on prosecutorial discretion, similar in purpose to the grand jury but with key differences, including the defendant's ability to cross-examine witnesses and present evidence.
Special and Investigative Grand Juries
In addition to regular grand juries, federal and some state courts can convene special grand juries. These are typically empaneled to investigate complex matters like organized crime, public corruption, drug trafficking, or large-scale fraud. Special grand juries may sit for longer terms, sometimes up to 36 months with extensions, and they often have broader investigative mandates.
Some states also maintain civil grand juries, which are separate from criminal grand juries. Civil grand juries investigate the operations of local government agencies, review spending, and issue public reports with recommendations. In California, for example, each county empanels a civil grand jury annually to serve this watchdog function.
Why Grand Jury Proceedings Are Secret
Grand jury secrecy is one of its defining characteristics. Federal Rule of Criminal Procedure 6(e) imposes strict secrecy obligations on prosecutors, grand jurors, court reporters, and other participants. Witnesses, notably, are generally not bound by these secrecy rules and may discuss their testimony publicly.
| Reason for Secrecy | Explanation |
|---|---|
| Protect the accused | Prevents damage to the reputation of individuals who are investigated but not charged |
| Encourage honest testimony | Witnesses may speak more freely knowing their statements are confidential |
| Prevent flight | Keeps targets from learning about the investigation and fleeing |
| Prevent evidence tampering | Reduces the risk that subjects will destroy evidence or intimidate witnesses |
| Protect grand jurors | Shields jurors from outside pressure, threats, or retaliation |
Violations of grand jury secrecy can result in contempt of court charges. Courts take these obligations seriously, and unauthorized disclosures can lead to sanctions, dismissal of charges, or other judicial remedies. In rare circumstances, courts may authorize limited disclosure of grand jury materials, such as when they are needed for another judicial proceeding.
Frequently Asked Questions
Can a grand jury decline to indict?
Yes. A grand jury can return a "no bill," meaning it has determined there is insufficient evidence to charge the accused. While this outcome is relatively uncommon (federal grand juries indict in the vast majority of cases), it does happen. The prosecutor may choose to re-present the case to another grand jury or pursue alternative charging methods.
Can the accused testify before the grand jury?
In most jurisdictions, the accused does not have the right to testify before the grand jury. However, some jurisdictions allow a target of the investigation to request an opportunity to testify. Whether to grant such a request is typically at the prosecutor's discretion. If the accused does testify, they are subject to questioning by the prosecutor and grand jurors, and they have the right to invoke the Fifth Amendment.
How long does a grand jury investigation last?
Grand jury terms vary. A federal grand jury sits for up to 18 months and can be extended to 24 months by the court. Some state grand juries serve for shorter periods. A single case may be presented in a matter of hours, while complex investigations can span the entire term of the grand jury.
Can a witness refuse to testify?
A witness can invoke the Fifth Amendment privilege against self-incrimination and refuse to answer specific questions. However, if the prosecutor grants the witness immunity, the privilege no longer applies, and the witness must testify. Refusing to testify after being granted immunity can result in a civil contempt finding and incarceration until the witness complies or the grand jury term expires.
Are grand jury proceedings open to the public?
No. Grand jury proceedings are conducted entirely in secret. The public, media, defense attorneys, and the accused are not permitted to attend. This secrecy is enforced by law and is maintained even after the grand jury's term ends, with limited exceptions ordered by a court.
Is a grand jury required for all criminal cases?
No. In the federal system, a grand jury indictment is required for felonies but not for misdemeanors. At the state level, requirements vary significantly. Many states allow prosecutors to bring felony charges through a preliminary hearing and information rather than a grand jury indictment. About half of all states require grand jury involvement for at least some categories of felonies.