Over in this thread, there’s a discussion of the degree to which sworn testimony can be given that would suit a very narrow interpretation of a question, even if the answer may be misleading to a more general point.
When I go for jury duty, during voir dire, I am sworn to tell the whole truth, and on at least two occasions I can recall, the judge has explained that “the whole truth” means that prospective jurors are under the obligation to offer relevant information within the spirit of the question. (It is phrased more elegantly, but the jist is that if an attorney were to ask me if I have a family member who works for the police, I should volunteer that I have an cousin who works for the FBI, even if I am unsure whether a cousin is actually a family member or whether an FBI special agent is actually a police officer within the context of the question.)
Is there a generally accepted standard for how forthcoming a sworn statement must be? To what extent is sworn testimony expected to illuminate issues that may not be directly called upon due to the precise wording of a question?
Is the obligation to provide related information different for a potential juror in voir dire, compared to a witness on civil or criminal matters?
Again, I’m not asking about the risk of someone to be prosecuted for excessively narrow answers to questions, I’m asking about the general understanding of what the oath means in relation to being sworn to tell the truth.
General expectations exist based on the role of the person offering the sworn statement. A lawyer may not even be under oath, but he has a duty of candor towards the tribunal. He can argue evidence and its interpretation as a zealous advocate for his client; he is expected not to deceive the court about factual matters that he represents as true.
A witness, called for one side, is understood to have a duty to answer truthfully the questions posed by the other side, but there is no expectation he will volunteer useful information that is relevant but not directly responsive.
A juror, having no “side,” would be somewhat more expected to be forthcoming, but even then, the voir dire will typically end with an open-ended question like, “Is there any other reason you could not be seated as a juror for this trial, and fairly weigh the evidence presented?”
I’m not aware of any formalized requirements that go beyond the extant standards for perjury, etc.
Our oath is “the truth, the whole truth, and nothing but the truth.” A reasonableness test is applied, if someone omits or fudges: would a reasonable person, hearing that testimony or statement, draw a fair inference from it? Would a reasonable person expect or want to know more? And (perhaps most importantly) would a reasonable judge or magistrate get pissed off if he later learned that there was more to the story than the witness or juror said?
When in doubt, spill it, or ask for a sidebar. Better to say something that the court doesn’t really need to hear, than to withhold it and have it be relevant, or even dispositive.