I wonder why both cases aren't being tried together? That would seem the more logical way to do things, as both sets of charges are basically linked. Is it because one lot is state and the other federal?
From my two lots of jury service, I can say that I'd find it very odd to have to rule on one charge, with evidence of another but no idea how to weigh it. If you've got a previous conviction, then you know that this evidence has gone through its own jury trial, so you can rely on it. Admittedly once you've found someone guilty yourself, and they've gone off to prison, you are fully aware that the justice system isn't perfect by any means - and just how uncertain every decision must be. But to be given evidence of a related crime that you can't weigh fully, becuase you're not getting it all seems very odd. And if they are giving you all the evidence, then why aren't you finding on that case too?