It's a very interesting and complicated question.
With few exceptions, we have resisted any kind of jury vetting on the front end. In the U.S., there is a very extensive voir dire system where potential jurors are asked a number of questions by the lawyers about features that might have a bearing on their jury service. We have not gone that route for all sorts of reasons—for reasons of juror privacy but also because we sort of have to assume that jurors are in a position to serve.
If we start asking too many questions, it's problematic. On the one hand, it might make sense to say, “Well, maybe we should consider asking jurors if they think they might be impacted.” With that type of inquiry, the rationale might come from a very good place, but then, of course, the flip side is the significant risk of stigma, the significant risk that, all of a sudden, we're looking for a particularly mentally fit type of juror, and that kind of inquiry is a lot darker.
Occasionally, there are questions about whether we should question jurors about their competence. There have been some very high-profile cases in the past. In the U.K., for example, it came out after a trial that there was obviously not a basic understanding on the part of jurors of the legal concepts, and those things can have a potentially devastating impact.
Again, the idea of asking jurors...of measuring their competence in advance, can go south very quickly. This kind of questioning raises a lot of difficult questions. I'm a skeptic.