A physics professor is lecturing. At one point he points to a formula on the board and says "And now, it's obvious that from this formula, this one follows" (writing another one). Then he stops, and says "Hold on a minute," and covers the board with equations while the students wait in silence. Finally he nods, and says "Yes, I was right! It is obvious that this follows from that."What does this have to do with grand jury duty? I'll tell you. I don't know how things are in other states, but in New Jersey whenever they want to try someone for a felony (or, in NJ-speak, an "indictable offense"), they have to bring their evidence to a grand jury to show they have a chance for a conviction, that they're not grasping at straws (or railroading some poor schmuck or political opponent). The idea is that if they can't get a) a simple majority of 23 people to agree, even when b) unopposed by defense lawyers, that c) there is a prima facie case for guilt, then they would just be wasting everyone's time at trial, where they need a) unanimity among 12 people, b) in the face of a vigorous defense, c) that the guy is guilty beyond a reasonable doubt.
Makes sense, I guess. It's just weird when there are disagreements about whether there is a prima facie case for something. It's like you can't give too careful an argument or it's not prima facie anymore, like in the joke (tertia facie?). Plus it's weird using a term like prima facie in non-philosophical contexts (of course, everyone else says "probable cause").
It's also funny hearing them read the law, where legislators have tried to cover all the bases in their definition (often this means lots of disjunctions, which for some reason can confuse people). "Knowing" that P turns out to mean being "aware" that P; while to do something "purposefully" is to do it "consciously." Glad we cleared that up.