Grand Juries basically listen to the prosecution present a portion of their case, just enough to try for the indictments. The defense does not get a chance to participate, so generally, the charges will stand, unless they are ridiculous, IMO. I think LE will able to show that it is logical that Mickey is not alive, since they should be able to show A: that he kidnapped her, possibly after hitting her with his truck B: that she was never seen again C: some of whatever other evidence they have, including how they know he was at WB where the bike was found
The Grand Jury is not convicting him, just agreeing with the prosecution, that yes, there is reason to believe that the charges have not been made in haste or without reason.
JMO
Thanks for answering. When they first charged him, I was wondering if the capital murder charge was made in hopes that he'd talk in exchange for a lesser charge. Can they really do that in real life?