I want to pose a question on the limits of a defendant's right to call people to testify at trial.

Let's assume that a judge is conducting a trial (the sort of trial is irrelevant - it could be criminal, civil, family or traffic court even), and the defendant calls the judge to the stand to testify - as a "hostile" witness if need be.

Does this action result in an automatic mistrial regardless of whether the judge accepted or refused to take the stand? Further, does a defendant have the right to subpoena and call anyone he wants to the stand, as a witness - even the president or the pope or a member of the jury? If the ridiculous witnesses he calls don't take the stand, is this also grounds for a mistrial since the witnesses he wanted were not heard in court?

  • 5
    I suspect that the lawyer would object to the judge before the trial if this were even possible.
    – Mary
    Commented Jun 16, 2023 at 0:09
  • 1
    if this were feasible, it'd be used a LOT to artificially delay trials by making it impossible to find a judge for them, don't you think? As people would deliberately call the judge as a witness precisely for the reason of throwing a spanner in the works of the court and forcing them to find and appoint a new judge, who then also would be called as a witness, in perpetuity.
    – jwenting
    Commented Jun 16, 2023 at 7:29
  • 5
    I seem to recall an example of this, with General Sir Anthony Cecil Hogmanay Melchett being called to testify in a court-martial over which he was presiding. Still, this was a very long time ago now...
    – AJM
    Commented Jun 16, 2023 at 11:27
  • 2
    that's actually where I got the idea for the question
    – Jon
    Commented Jun 16, 2023 at 11:53
  • 1
    @Jon Clever, clever!. Splendid, excellent, first-class...
    – AJM
    Commented Jun 16, 2023 at 18:25

3 Answers 3


Parties may only call witnesses for the purpose of adducing* admissible evidence. Evidence is only admissible if it is relevant. If a witness cannot give any relevant evidence, then a party has no right to call them or invoke the court's power to compel them to give evidence.

In practice, if there were any doubt about the witness's ability to give relevant evidence, it is likely that the court would allow the defendant to call the witness, if only for the purpose of a preliminary hearing where the parties can argue about whether the proposed evidence is actually admissible.

If a judge or juror is able to give relevant evidence about a case, they should recuse themselves. If a judge does not recuse, or does not permit the defendant to call some other witness having decided that the witness could not give relevant evidence, these decisions can be reviewed on appeal.

The standard required to overturn the judge's decision varies depending on the jurisdiction, but generally the defendant would have to show that the evidence they were not permitted to adduce was also material. This might prevent a mistrial from occurring in cases where, for example, the defendant was not permitted to call the President to give evidence about something that occurred at a public event the President attended. The President's knowledge of the event might be technically admissible, but plainly not likely to advance either side of the case, given the other evidence available. Of course, if the President can give relevant, admissible and material evidence about a fact in issue then the defendant would be entitled to call them.

*Adduce: cite as evidence.


The judge on the stand?

Properly Done: A witness must be listed or motioned for, and witnesses can be denied

Any party in a lawsuit needs to list all witnesses well in advance of the trial. Presenting the witness list is part of normal motion practice. The law is such that there should be no surprise witnesses because both parties need to be able to prepare for the witnesses.

If a new witness or evidence surfaces during the trial, there's a motion to present them. That motion can be oral, during the trial. But without such a motion, they can't be heard.

As such, the judge will review the request days to months in advance and deny the motion. The lawyer could try to appeal that, but unless he has extremely good reasons to get the judge into the witness stand, then the motion will be denied, because the judge is extremely rarely a relevant witness.

When the lawyer actually had such good reasons, then the judge would have needed to recuse themselves in the first place, and can't preside over the case.

In the heat of the moment

If the lawyer has the glorious idea to request the judge to take the stand during the trial, the Judge can do a lot of things, starting with denying the motion. If the lawyer does not stop, then the judge can order the lawyer to shut up, then fine them for contempt of court, and finally lock them up for contempt of court.

The proper way to deal with the ad-hoc motion being denied is to appeal the decision, which does not lead to a mistrial and if the denial was proper, nothing at all.

Who's a witness?

Only relevant people may be called as witnesses. Relevant means, that their testimony will lead to helping the case to progress.

Unless the sweet old lady that has to tell lots of good things about the accused actually has something case relevant to say, she is not a witness that can be called for anything but a character witness.

The President and pope would almost never be relevant witnesses, and so is the judge.

The judge can smack down any nonrelevant witness, and deny that they can be heard at all. It is up to the person calling the witness to establish that and how they are relevant, when they provide their list of witnesses to the court.


If you had any issue with the judge being a neutral and uninvolved party, you needed to raise it pre-trial.

You are to share your witness list pre-trial (so opposing counsel can depose them). Having the judge on that list is a prima-facie claim that the judge is involved. Opposing counsel will jump all over that, and force you to raise the issue pre-trial. Part of their job is to prevent anything which would give you a basis for an appeal. The likely result is that the judge will be recused and you'll get another judge assigned.

To add the judge as a witness mid-trial, you'd need to show

  • a legitimate reason to have failed to mention it pre-trial.
  • why you are not simply arguing for a mistrial due to judge disqualification (which ends the trial and moots the point). Be very careful here: you are implicitly claiming the judge remains qualified, and as such, forfeiting your right to claim otherwise later.
  • and lastly, why it's relevant.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .