The last time I was summoned for jury duty it was mid-week in January, and I made a point of telling the lawyers during questioning that I would have to be home before sunset on Friday. They were not concerned (and I was picked for the jury, and they settled the case an hour later so it ended up not mattering). A friend was recently seated on a jury where the trial ran longer than anticipated and they convened court on Saturday. My understanding is that they were told, not asked, about this scheduling. This made me wonder how one ought to handle this as a juror. I would hope that the answer is not "always try to get out of jury duty" because this is an important civic obligation that we should take seriously if we can do it without violating halacha.
So my question is: how do courts handle trials that run into Shabbat where somebody on the jury cares, and what is the right thing to do as a prospective juror?