The answer to a question from Aguila Blanca is moot, now that Rittenhouse has been found not guilty on all counts. I think that was the correct result from what I know about the case. But I will answer AB's question anyway.
If that had been the case and the alternate jurors had not been reading the news, etc., then they possibly could have been substituted for jurors "tainted" by outside influences. That is somewhat dependent upon state rules. In my state, sometimes the judge will admonish alternate jurors not to discuss the case, etc. until after a verdict is rendered just in case a sitting juror gets sick, etc. But I can only remember 1 or 2 cases this ever happened.
There are still six alternate jurors hanging around the courthouse. If the judge is made aware that some of the active jurors are either refusing to or unable to deliver a verdict because of outside intimidation, could the judge simply toss those jurors, replace them from the pool of alternates, and have the jury re-commence deliberations?
If that had been the case and the alternate jurors had not been reading the news, etc., then they possibly could have been substituted for jurors "tainted" by outside influences. That is somewhat dependent upon state rules. In my state, sometimes the judge will admonish alternate jurors not to discuss the case, etc. until after a verdict is rendered just in case a sitting juror gets sick, etc. But I can only remember 1 or 2 cases this ever happened.