I mean, is courtroom attendance mandatory when given a summons? What are the repercussions for failing to turn up during the appointed date and time? I know that they have Voir Dire and names of American citizens are selected randomly from the electoral roll (the same one used for federal elections on selecting a new president in office) unless you renounced US citizenship which rescinds both your right to vote and potential jury duty.


It is, though there are some exceptions depending on circumstances (e.g. if you are someone’s caregiver and taking time away could be life threatening).
A warning, fines, and potentially jail time, in that order.
Technically anyone can be asked to serve on a jury as long as they are of age, but the electoral rolls are the usual pool they pull from because it’s easier to confirm a valid area of residence that way.
Beyond that, you get a summons in the mail. That summons will either be for trial jury or grand jury.
Grand jury usually specifies a window of time (a month or so) with days of the week that you may have to serve, during which time you review cases and determine what should go to trial.
Trial jury is usually a single day, but that single day could have multiple cases, or it could involve a more complicated case that lasts multiple days.
In both cases, the usual practice is that you are given a number to call the night before you’re asked to report in, which will tell you if you are needed or not.
If they tell you that you have to report in, you go to the court and they give you a number. They will then screen people in order of their number to determine if they are appropriate for the case (e.g. someone who works for a bank might have too much personal bias for a case involving a bank robbery).
If you are screened and deemed not appropriate, they’ll let you leave. And once they have enough people to fill a jury plus any potential alternates (in case the trial may be lengthy, where jurors may need to be subbed out), everyone else who had yet to be screened can then leave.
In the rare cases where you end up on a jury that lasts for several days, the court is supposed to offer a fixed amount of financial compensation to make up for work you are missing, though it’s usually a paltry sum compared to what a full time worker would otherwise make. But at least you have job security, because it is illegal for an employer to fire sometime for missing work due to jury duty (as long as you tell them first).
Upon completion of jury duty, you will get some sort of document proving you attended, which you can present to your employer for proof and to also get out of subsequent jury duty summons for a limited time if you can show that you just served.
One other note is that there is a difference between state and federal jury. State crimes are tried by the state and federal crimes are tried by the fed. Depending on the state, recent attendance of federal jury may be enough to exempt you from having to serve in a state jury, but I’ve never seen it work the other way around. You can serve on a state jury and not have to worry about the state calling you in for another few years, but the fed can still summon you for federal jury duty the following week and there’s nothing you can do.
Are there exclusions for Jury Duty in the US based on occupational fields such as:
For any of those reasons: one should present proof of current employment within those sectors (for armed forces, such as CAC card or DoD idetification to guarantee exclusion or relevant credentials & ID’s telling them you’re in LE). And of course, Ex-Cons who are convicted of serious crimes are not eligible to serve as jurors.
Occupation does not automatically disqualify you unless your work connects you to the case in question, but some occupations are not going to make it through voir dire. Keep in mind that you might be sitting on a jury in a civil case. Rather famously, Barack Obama was summoned (after his presidency) and he went, but was dismissed by random draw.