The Grand Jury in the United States

The grand jury system, an institution of English-speaking countries, was established in the US by the fifth amendment to the Constitution. It is a codified practice of Anglo-Saxon or Norman (depending upon your expert) common law. "The grand jury is supposed to function as a body of neighbors who aid the state in bringing criminals to justice while protecting the innocent from unjust accusation," according to Consumer Law.

All but two states and the District of Columbia use grand juries to indict, according to the University of Dayton law school; Connecticut and Pennsylvania have retained the investigating grand jury. A subset of these states, 23, require that grand jury indictments be used for specific crimes; Texas is in this subset.

What is a Grand Jury
A grand jury is a group of citizens, usually chosen from the same pool as trial jurors, that is sworn in by a court to hear a case. The grand jury is composed of not less than 12 and not more than 23 persons; and in the Federal courts, the number shall not be less than 16 nor more than 23.

Grand juries differ from trial juries (which consist of 12 jurors) in other significant ways:

• Unlike trial juries, grand juries can indict with only a majority (not unanimous) vote.
• Trial juries decide whether a defendent is guilty or not guilty of a crime. A grand jury listens to evidence and decides if someone should be charged with a crime. Thus the grand jury determines probable cause, not "guilt" or "innocence". According to the American Bar Association:
  Since the role of the grand jury is only to determine probable cause, there is no need for the jury to hear all the evidence, or even conflicting evidence. It is left to the good faith of the prosecutor to present conflicting evidence.
• Unlike trial juries, grand juries do not usually convene daily. Many federal grand juries sit only once a week or twice a month.

The Subpoena
Grand juries can use the power of the court to subpoena (command) evidence although they can also invite (not command) witnesses to testify.

Should you receive a subpoena but think you should not have to testify, or you think what the subpoena asks is "unreasonable or oppressive," you can file a motion to quash the subpeona. If you simply refuse to do what the subpoena asks, you can be held in civil (not criminal) contempt. If you are held in civil contempt, you will be jailed until you agree to comply with the subpoena or until the grand jury's term ends, whichever comes first.

Witness Right to Counsel
In a jury trial, defendents have a right to counsel; the lawyer sits alongside the defendent in the courtroom. In a grand jury investigation:

In the federal system, a witness cannot have his or her lawyer present in the grand jury room, although witnesses may interrupt their testimony and leave the grand jury room to consult with their lawyer. A few states do allow a lawyer to accompany the witness; some allow the lawyer to advise his or her client, others merely allow the lawyer to observe the proceeding.