By the time the United States Constitution and the Bill of Rights were drafted and ratified, the institution of trial by jury was almost universally revered, so revered that its history had been traced back to Magna Carta. The jury began in the form of a grand or presentment jury with the role of inquest and was started by Frankish conquerors to discover the King's rights. Henry II regularized this type of proceeding to establish royal control over the machinery of justice, first in civil trials and then in criminal trials. Trial by petit jury was not employed at least until the reign of Henry III, in which the jury was first essentially a body of witnesses, called for their knowledge of the case; not until the reign of Henry VI did it become the trier of evidence. It was during the Seventeenth Century that the jury emerged as a safeguard for the criminally accused. Thus, in the Eighteenth Century, Blackstone could commemorate the institution as part of a ''strong and two-fold barrier . . . between the liberties of the people and the prerogative of the crown'' because ''the truth of every accusation . . . . [must] be confirmed by the unanimous suffrage of twelve of his equals and neighbors indifferently chosen and superior to all suspicion.'' The right was guaranteed in the constitutions of the original 13 States, was guaranteed in the body of the Constitution and in the Sixth Amendment, and the constitution of every State entering the Union thereafter in one form or another protected the right to jury trial in criminal cases. ''Those who emigrated to this country from England brought with them this great privilege 'as their birthright and inheritance, as a part of that admirable common law which had fenced around and interposed barriers on every side against the approaches of arbitrary power.'''
''The guarantees of jury trial in the Federal and State Constitutions reflect a profound judgment about the way in which law should be enforced and justice administered. A right to jury trial is granted to criminal defendants in order to prevent oppression by the Government. Those who wrote our constitutions knew from history and experience that it was necessary to protect against unfounded criminal charges brought to eliminate enemies and against judges too responsive to the voice of higher authority. The framers of the constitutions strove to create an independent judiciary but insisted upon further protection against arbitrary action. Providing an accused with the right to be tried by a jury of his peers gave him an inestimable safeguard against the corrupt overzealous prosecutor and against the compliant, biased, or eccentric judge. . . . [T]he jury trial provisions . . . reflect a fundamental decision about the exercise of official power--a reluctance to entrust plenary powers over the life and liberty of the citizen to one judge or to a group of judges. Fear of unchecked power . . . found expression in the criminal law in this insistence upon community participation in the determination of guilt or innocence.''
A Grand Jury derives its name from the fact that it usually has a greater number of jurors than a trial (petit) jury. One of the earliest concepts of Grand Juries dates back to early Greece where the Athenians used an accusatory body. In early Briton, the Saxons also used something similar to a Grand Jury System. During the years 978 to 1016, one of the Dooms (laws) stated that for each 100 men, 12 were to be named to act as an accusing body. They were cautioned "not to accuse an innocent man or spare a guilty one."
The Grand Jury can also be traced to the time of the Norman conquest of England in 1066. There is evidence that the courts of that time summoned a body of sworn neighbors to present crimes that had come to their knowledge. Since the members of that accusing jury were selected from small jurisdictions, it was natural that they could present accusations based on their personal knowledge.
Historians agree that the Assize [court session or assembly] of Clarendon in 1166 provided the ground work for our present Grand Jury system. During the reign of Henry II (1154-1189), to regain for the crown the powers usurped by Thomas Becket, Chancellor of England, 12 "good and lawful men" in each village were assembled to reveal the names of those suspected of crimes. It was during this same period that juries were divided into two types, civil and criminal, with the development of each influencing the other.
The oath taken by these jurors provided that they would carry out their duties faithfully, that they would aggrieve no one through enmity nor deference to anyone through love, and that they would conceal those things that they had heard.
By the year 1290, these accusing juries were given the authority to inquire into the maintenance of bridges and highways, defects of jails, and whether the Sheriff had kept in jail anyone who should have been brought before the justices. "Le Grand Inquest" evolved during the reign of Edward III (1368), when the "accusatory jury" was increased in number from 12 to 23, with a majority vote necessary to indict anyone accused of crime.
In America, the Massachusetts Bay Colony impaneled the first Grand Jury in 1635 to consider cases of murder, robbery and wife beating. As early as 1700, the value of the Grand Jury was recognized as opposing the Royalists. These colonial Grand Juries expressed their independence by refusing to indict leaders of the Stamp Act (1765), and refusing to bring libel charges against the editors of the Boston Gazette (1765). A union with other colonies to oppose British taxes was supported by the Philadelphia Grand Jury in 1770.
By the end of the Colonial Period, the Grand Jury had become an indispensable adjunct of Government: "they proposed new laws, protested against abuses in government, and wielded the tremendous authority in their power to determine who should and who should not face trial."