Grand Juries don’t convict anyone of anything. That isn’t their role. They say things like “yes, those sound like valid charges, take it to trial!”, or “no, that is totally bogus, forget about it, no trial”.
They have a way lower standard then “beyond a reasonable doubt”, I’m sure it has a legal term, but I call it “oh, that sounds fishy”.
So generally cops arrest someone, a DA says “yeah, I think I could prove that, take it to court”, and a grand jury can derail that by saying “forget it”, but normally they rubber stamp things. In theory they are important, but in practice it is easy for people on a grand jury to think “well they could be guilty, and if so it would be terrible to let them go, and if they are innocent the trial will prove it…”.
At any rate, yeah, if they were convicted it wasn’t by a Grand Jury…but a Grand Jury would have had to say “yeah, there is smoke here! Go check for a fire!” long before a regular jury can say “Guilty!”
