Once again: Are you an investigator, the alleged victim or the suspect? If none of those, what is your connection to the situation?
What is "Rule 21"?
Title 4 of the California Rules of Court covers criminal cases, but there is no "Rule 21." Since you asked about changing venue, that subject is covered in Ch. 2 of Division 2 of Title 4 (Rules 4.150-4.155), and the law regarding changes of venue is found in
Ch. 6 of Title 6 of Part 2 of the Penal Code (starting with section 1033). Is "Rule 21" some sort of local rule in the unidentified county where the case is pending? Or is this a federal prosecution?
Investigators and cops and prosecutors are presumed to have a bias against criminal defendants. Whether a change of venue might be appropriate depends on actual facts (not factual conclusions).
We don't know any such thing. It also makes no sense since a trial won't begin until the jury is empaneled.
In the abstract, virtually anything is possible.