Justice Scalia did NOT say it can’t be done. Otherwise, he would have ruled against Williams.
Here’s what he wrote, repeating from post #9 above:
“The grand jury requires no authorization from its constituting court to initiate an investigation, nor does the prosecutor require leave of court to seek a grand jury indictment.”
That’s the Supreme Court’s ruling and there is no confusion in it. It does not need to be initiated by a court or a prosecutor.
A group of concerned citizens can convene a grand jury and file a notice if they desire in court to allow the members of the grand jury to deliberate under its auspices, meaning that any of its findings and indictments are recorded under seal by the court.
Now there will be with high probability at least one federal court that will accept a ‘Scalia Grand Jury’ to make its presentments to the court and to prosecutors. For example, Freepers taking a template by yours truly were able to get a matter before Governor Greg Abbott of Texas when he was the State AG and to provide him with the template to write a preliminary injunction against Barack Obama’s DAPA program that sought to evade Congress and amnestize millions of illegal aliens and where AG Abbott was able to find a suitable federal judge in Judge Hanen of the Southern District of Texas. So it can be done with a number of subject matter jurisdictions such as violations of 4th Amendment rights or stealing of property owned by the public (for example, destruction of government property in an off-site server containing official communications). There are dozens of subject matter jurisdiction items that can form a foundation for a grand jury.
It is constitutional and cannot be barred. That was the whole point of US v. Williams referenced above. Prosecutors cannot refuse to act on its findings and indictments unless rights have been violated, and even then it is case by case, point by point, as Justice Scalia, so clearly described.
It is very similar to a group calling the police to report a crime with witnesses standing ready to give their testimony. The police cannot refuse to take a report and to act on it.
What Scalia was conveying in US v. Williams is that the courts have allowed over time for the grand jury to become ‘owned’ by government courts and prosecutors, while the people have forgotten that the grand jury is theirs. Scalia was reminding the nation in his decision that the courts and prosecutors have no title to grand juries, they are a property of any group that wishes to create and convene one, with a natural expectation that an independently formed grand jury will want to interact with a court and a prosecutor, hence they will seek and file for recognition on a case. It’s expected, but not necessary.
Did you read the opinion? Williams lost.
Williams was asking the courts to force the prosecutor to present exculpatory evidence to the grand jury. Scalia ruled against him, holding that the courts don't interfere in the grand jury's proceedings except for: (1) calling the grand jury into existence, (2) swearing the grand jurors in, and (3) enforcing (or refusing to enforce) grand jury subpoenas.