The traditional system was that persons qualified to be members of Juries (freeholders aged over 21) were called by County Sherriff’s to Assizes (Now Crown Courts) and divided into “Grand” and “Petit” juries.
Grand Juries heard accusations of crimes and decided whether there was a case to answer. If there was, The Crown was required to place the matter before a Petit Jury.
Members of a Grand Jury could also make investigations on their own initiative as a posse.
The authority of a Grand Jury comes from the subject’s right to be tried by his Peers per Chapter 39 of Magna Carta 1215:
No freeman shall be taken or imprisoned, or disseised of his freehold, or liberties, or free customs, or outlawed, or exiled, or any otherwise destroyed; nor will we not pass upon him, nor condemn him, but by lawful judgment of his peers, and by the law of the land.
The right of Grand Juries to present their verdicts to The Sovereign is acknowledged in Articles 5 and 11 of the Bill of Rights 1688:
5. Right to petition. That it is the Right of the Subjects to petition the King and all Commitments and Prosecutions for such Petitioning are Illegall...
11. Juries. That Jurors ought to be duely impannelled and returned ...
Both Magna Carta 1215 and the Bill of Rights are “statutes in force”. As with many legal terms, “statute” has more than one definition. In these cases they were re-statements of the common law by The Sovereign as an exercise of the Royal Prerogative. No Parliaments were involved because in there had been lawful rebellions and “trial by battle” had settled the issue on both occasions (see footnote).
This also means that no Parliament has authority to infringe their provisions. This is also acknowledged in Article 13 of the Bill of Rights:
13. Frequent Parliaments. And that for Redresse of all Grievances and for the amending strengthening and preserveing of the Lawes Parlyaments ought to be held frequently...
“Amending” is a legal term which means “to improve”. “Strengthen” and “preserve” have their natural meaning. There is no lawful authority for a Parliament to infringe the subjects Common Law rights.
Returning to the fate of Grand Juries post 1917, the Administration of Justice (Miscellaneous Provisions) Act 1933 was passed which was described as “An Act to abolish grand juries and amend the law as to the presentment of indictments;”. That Act was later repealed and the practice of accepting the signature of a Court Official, instead of that of the foreman of a Grand Jury on indictments (formal charges requiring a jury trial) has continued on dubious legal grounds.
There are in force at least two statutes which still require trial by Grand Jury. The first is known as “Statute the Fifth of 1351”:
IV. None shall be taken upon Suggestion without lawful Presentment; nor disfranchised, but by Course of Law.
Whereas it is contained in the Great Charter of the Franchises of England, that none shall be imprisoned nor put out of his Freehold, nor of his Franchises nor free Custom, unless it be by the Law of the Land; It is accorded assented, and stablished, That from henceforth none shall be taken by Petition or Suggestion made to our Lord the King, or to his Council, unless it be by Indictment or Presentment of good and lawful People of the same neighbourhood where such Deeds be done, in due Manner, or by Process made by Writ original at the Common Law; nor that none be out of his Franchises, nor of his Freeholds, unless he be duly brought into answer, and forejudged of the same by the Course of the Law; and if any thing be done against the same, it shall be redresseed and holden for none...
This is another example of a statute made by The Sovereign.
Now we turn to a statute in force made by a Parliament which requires that Grand Juries be embodied:
V. Indictment must be found by a Grand Jury within Three Years.
And to the intent that the Terror and Dread of such Criminal Accusations may in some reasonable time bee removed That . . . F1 noe Person or Persons whatsoever shall bee indicted tryed or prosecuted for any such Treason as aforesaid or for Misprision of such Treason that shall bee committed or done within the Kingdome of England Dominion of Wales or Towne of Berwick upon Tweed . . . F1 unlesse the same Indictment bee found by a Grand Jury within Three Years next after the Treason or Offence done and committed...
There we have it, Grand Juries never went away, they have been conveniently forgotten by the present establishment. That does not mean they can get away with it. In Bowles.v. Bank of England (1913) it was ruled that:
The Bill of Rights remains unrepealled and practice or custom, however prolonged ... cannot be relied on by the Crown as justifying any infringement of its provisions.
If the present legal establishment fails to do their duty, freeholders aged over 21 may, on their own authority, form Grand Juries to investigate and indict criminals.
Footnote:
Here is confirmation from Blackstone’s Commentaries that “Right of War” sets lawful title to The Crown and the limitations which bind the King:
THIS conquest then by William of Normandy was, like that of Canute before, a forcible transfer of the crown of England into a new family: but, the crown being so transferred, all the inherent properties of the crown were with it transferred also. For, the victory obtained at Hastings not being a victory over the nation collectively, but only over the person of Harold, the only right that the conqueror could pretend to acquire thereby, was the right to possess the crown of England, not to alter the nature of the government. And therefore, as the English laws still remained in force, he must necessarily take the crown subject to those laws, and with all it's inherent properties; the first and principal of which was it's descendibility. Here then we must drop our race of Saxon kings, at least for a while, and derive our descents from William the conqueror as from a new stock, who acquired by right of war (such as it is, yet still the dernier resort of kings) a strong and undisputed title to the inheritable crown of England...
Blackstone's Commentaries on the Laws of England
Book the First : Chapter the Third : Of the King and His Title P 193.