A grand jury is a jury empowered by law to conduct legal proceedings, investigate potential criminal conduct, and determine whether criminal charges should be brought. A grand jury may subpoena physical evidence or a person to testify. A grand jury is separate from the courts, which do not preside over its functioning.
Originating in England during the Middle Ages, modern examples include grand juries in the United States, and to a lesser extent, Liberia. In Japan, there are citizen Prosecutorial Review Commissions which review cases that have been dropped by the prosecution, but they are not required for an indictment like in the previous two. Grand juries perform both accusatory and investigatory functions. The investigatory functions of grand juries include obtaining and reviewing documents and other evidence, and hearing sworn testimonies of witnesses who appear before it; the accusatory function determines whether there is probable cause to believe that one or more persons committed a particular offense within the jurisdiction of a court. While most grand juries focus on criminal matters, some civil grand juries serve an independent watchdog function. Around the 18th and 19th-century in Ireland and the U.S., grand juries were occasionally formed to pass or approve public policy.
The grand jury (from the French word grand meaning "large") is so named because traditionally it has more jurors than a trial jury, sometimes called a petty or petit jury (from the French word petit meaning "small"). A grand jury in the United States usually has 16 to 23 members, though in Virginia it has fewer members for regular or special grand juries.
Purpose The grand jury has been described as a "shield and sword""Law on the Books: Shield and Sword". America's Courts and the Criminal Justice System. 1999. p 247. that has both an offensive purpose and defensive purpose.Statement of Sara Sun Beale. Constitutional Rights and the Grand Jury. p 18. It has been called the shield of the people against the power of the crown;HL Deb, 17 July 1812, col 1091 though Green says this is a myth.Diamond. Federal Grand Jury Practice and Procedure. 5th Edition. p 1-5. It has been described as the "sword of the people"Judicial Council of California. 1 January 1974. p 30. and as a sword of the crown.Bennett. Environmental Crime: Pollution and Wildlife Enforcement. p 39
Federal courts in the United States have nonetheless repeatedly affirmed the grand jury's protective function. The U.S. Supreme Court has described the grand jury's “historic office” as providing “a shield against arbitrary or oppressive action, by insuring that serious criminal accusations will be brought only upon the considered judgment of a representative body of citizens." More recently, a federal district court reaffirmed that “the purpose of a grand jury is to serve as a shield against unjust prosecutions, not as a sword to rubber-stamp criminal charges."
Criminal The function of a grand jury is to accuse persons who may be guilty of a crime, but the institution is also a shield against unfounded and oppressive prosecution. It is a means for lay citizens, representative of the community, to participate in the administration of justice. It can also make presentments on crime and maladministration in its area. Traditionally, a grand jury consists of 23 members.
The mode of accusation is by a written statement of two types: in solemn form (indictment) describing the offense with proper accompaniments of time and circumstances, and certainty of act and person, or by a less formal mode, which is usually the spontaneous act of the grand jury, called presentment.
No indictment or presentment can be made except by concurrence of at least twelve of the jurors. The grand jury may accuse upon their own knowledge, but it is generally done upon the testimony of witnesses under oath and other evidence heard before them. Grand jury proceedings are, in the first instance, held at the instigation of the government or other prosecutors, and are done and in secret deliberation. The accused has no knowledge of nor right to interfere with their proceedings.
If they find the accusation credible, which is usually drawn up in form by the prosecutor or an officer of the court, they write upon the indictment the words "a true bill" which is signed by the foreperson of the grand jury and presented to the court publicly in the presence of all the jurors. If the indictment is not proven to the satisfaction of the grand jury, the word ignoramus or "not a true bill" is written upon it by the grand jury, or by their foreman and then said to be ignored, and the accusation is dismissed as unfounded; the potential defendant is said to have been "no-billed" by the grand jury. If the grand jury returns an indictment as a true bill (billa vera), the indictment is said to be founded and the party to stand indicted and required to be put on trial.
Watchdog In Japan, the Prosecutorial Review Commission is made up of 11 randomly selected citizens, is appointed to a six-month term, and its primary purpose is examining cases prosecutors have chosen not to continue prosecuting. It has therefore been perceived as a way to combat misfeasance in public officials. This is similar to civil grand juries in U.S. states like California.
Similarly, in 2011, there was a private member's bill in Ontario, Canada which would create citizen grand juries to oversee government institutions. The bill did not make any progress and was not passed.Bill 207, Grand Juries Act, 2011. Legislative Assembly of Ontario, 39th Parliament, Session 2.
Legislative
Many early grand juries in the U.S. had quasi-legislative functions like passing legislation or approving taxes or expenditures.
From the 17th century until 1898 in Ireland, Grand Juries also functioned as local government authorities:
Present-day use
United States
At the time of the founding of the United States, a grand jury indictment was required for almost all prosecutions, and juries rendered the final verdict of almost all criminal and civil cases. The Fifth Amendment to the Constitution of the United States reads, "No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a grand jury..."
In the early decades of the United States, grand juries played a major role in public matters. During that period counties followed the traditional practice of requiring all decisions be made by at least 12 of the grand jurors, (e.g., for a 23-person grand jury, 12 people would constitute a bare majority). Most criminal prosecutions were conducted by private parties, either a law enforcement officer, a lawyer hired by a crime victim or his family, or even by laymen. A layman could bring a bill of indictment to the grand jury; if the grand jury found that there was sufficient evidence for a trial, that the act was a crime under law, and that the court had jurisdiction, it would return the indictment to the complainant. The grand jury would then appoint the complaining party to exercise essentially the same authority as a state attorney general has, that is, a general power of attorney to represent the state in the case.
The grand jury served to screen out incompetent or malicious prosecutions. The advent of official public prosecutors in the later decades of the 19th century largely displaced private prosecutions.
In 1974, the second Watergate grand jury indicted seven White House aides, including former Attorney General John Mitchell, and named President Nixon as a "secret, un-indicted, co-conspirator". Despite evading impeachment by resigning from office, Nixon was still required to testify before a grand jury. In 1998, President Bill Clinton became the first sitting president required to testify before a grand jury as the subject of an investigation by the Office of Independent Counsel.
While all states have provisions for grand juries as of 2003, today approximately half of the states employ them and 22 states have provision to prevent the abolition of grand juries by legislatures or courts as of 2003. Six states (Oklahoma, Nebraska, New Mexico, North Dakota, Nevada, and Kansas) allow citizens to circulate a petition in order to impanel a grand jury.
An American federal grand jury has from 16 to 23 jurors, with twelve votes usually required to return an indictment. All grand jury proceedings are conducted behind closed doors, without a presiding judge. The prosecutors are tasked with arranging for the appearance of witnesses, as well as drafting the order in which they are called, and take part in the questioning of witnesses. The targets of the grand jury or their lawyers have no right to appear before a grand jury unless they are invited, nor do they have a right to present exculpatory evidence.
Although prosecutors present evidence, federal grand jurors are not passive recipients of the government’s case. Jurors may question witnesses, request that additional witnesses or documents be subpoenaed, and decline to indict even when prosecutors recommend doing so.;
If jurors believe a prosecutor is acting improperly or presenting misleading information, they may report that conduct to the supervising judge.;
In the United States, grand jury refusals to indict (known as "no-bills") have historically been rare. Federal court data showed that in fiscal year 2010, approximately 11 of roughly 162,000 proposed federal indictments resulted in no-bills; in fiscal year 2013, the figure was approximately 5 out of more than 165,000.; Beginning in late 2025, legal observers documented a marked increase in no-bill decisions in federal cases, particularly in matters arising from protest-related activity.; ;
Even an indictment that does not result in conviction can carry significant consequences for the accused, including legal defense costs, reputational damage, and a potential chilling effect on others' conduct. In the United States federal system, courts treat the grand jury's probable cause determination as effectively conclusive and rarely set indictments aside prior to trial.;
Japan
After World War II, under the influence of the Allies, Japan passed the Prosecutorial Review Commission Law on July 12, 1948, which created the Kensatsu Shinsakai (or Prosecutorial Review Commission (PRC) system), analogous to the grand jury system in the United States. Until 2009, the PRC's recommendations were not binding, and were only regarded as advisory. A survey conducted by the Japanese Cabinet Office in October 1990 showed that 68.8% of surveyed Japanese citizens were not familiar with the PRC system. On May 21, 2009, the Japanese government introduced new legislation which would make the PRC's decisions binding. A PRC is made up of 11 randomly selected citizens, is appointed to a six-month term, and its primary purpose is examining cases prosecutors have chosen not to continue prosecuting. It has therefore been perceived as a way to combat misfeasance in public officials. This an inverse of American grand juries, as they investigate if a case should be reinstated after being dropped by the prosecution, as opposed to if there is probable cause for changes to be laid in the first place. In this sense, a Japanese PRC functions for the benefit of the one pressing charges, as opposed to being a check on prosecutorial power.