In Colorado, county grand juries are governed by
Rule 6, Colorado Rules of Criminal Procedure.
You're on the right track with these good questions:
First, a new murder charge brought against BM would have to go through all the usual procedural steps. Although an indictment is based on the grand jury's finding of probable cause and could fulfill that hearing requirement, BM could challenge the finding and ask the new judge to review the GJ record. BM could also raise challenges on other grounds, including prosecutorial misconduct during the grand jury proceedings. If the judge decided the grand jury's finding of probable cause was unfounded or if there were other fatal errors, s/he could dismiss the charge.
I don't see the issue of bail eligibility anywhere in the grand jury's scope of authority. The bail statute and the Colorado Constitution seem to make this a decision for the court.
All the above, by way of saying that preliminary proceedings similar to what we've seen will likely be needed if an indictment were to issue from a grand jury.
The prosecution initiates the grand jury procedure by filing a petition with the Chief Judge, but you're right that it is the chief judge who orders the jury to be convened. He could find the request to be unjustified, at least theoretically. The petition would have to recite that the grand jury's investigative powers (including subpoenas, Rule 6.1) and secrecy are necessary, e.g., to assure the cooperation of witnesses (SD for example).
All grand juries operate in secrecy (see Rule 6.2) but their proceedings are recorded and the transcript is available to the defendant and the court after an indictment is issued. Whether the secrecy of proceedings can be maintained when meetings are conducted remotely via Zoom, WebEx, or similar technology would be an issue for the chief judge to decide. I am not aware of any appellate cases in Colorado that have considered the i
nformation on the NDAA website.
If I understand your point correctly, it is that the decision to convene a grand jury is not made lightly by the DA alone, ITA. I hope my prior post did not suggest otherwise. In addition to the procedural steps to be followed, LS will have to be prepared to commit substantial staff time and investigative resources to support the grand jury. Molly Chilson argued in the BE case that she would have to delegate her full time caseload in order to run the grand jury, and that she would need an additional deputy to bear the burden. When the commissioners refused the additional budget, she weighed the likely benefit to the BE investigation against the harm to the DA's office and its existing cases, and decided not to pursue the GJ option at the time.
To the best of my knowledge, that resource issue has not gone away. We'll see if DA LS can make it happen where Chilson did not, and how the public reacts either way.
Colorado attorney H. Michael Steinburg's website has a lot of readable information generally about criminal law, and the site has
a page on grand juries that is particularly rich.