Forgive me if this sounds stupid, but, if they are truly not worried about persons incriminating themselves, and they are saying this on live t.v., they are obviously not making said "persons" comfortable with this fact when they've come in to talk to them. I mean, give them something in writing.
Reporter: Have you offered immunity...?
AG: It's not really a question of immunity. Ah, uh, I, uh, will not answer that. It's a question of what your focus is.
Well, then, I can tell you, that they are not going to talk to you Mr. Dewine. Just recently one of the former, highest powers, in our country has asked for immunity in exchange for being interviewed. If the person(s) you are interviewing have critical information that would aid in solving the murders of eight human beings, and locking away a very dangerous animal(s), then grant them immunity in exchange for their interview (Unless of course they played a role in the murders, or are the head of an Ohio drug cartel, but I seriously doubt that either of these examples are the case.)
Honestly, why not just say; We know nothing new to tell you, and we aren't going to tell you what we do know. G'bye.
(Unless I missed something. Maybe I'm being too critical and pessimistic today.)
And seriously, on a side note, if I couldn't figure out who had the grows, by now, then I'd be very disappointed in myself. I guess they just wanted to see if anyone would actually answer the question, but saying that there were two locations, and which homes the grows were at, does not clear up what kind of operations they alluded to being at said homes, and what the family said was there. Personally, I tend to believe the family.
On a side note, I really do get the feeling that Reader cares.