My recollection is that he was willing to let BSL go free if he could bring Mickey home alive but that if she were dead, then forget it. I think what we are discussing now is a little bit different. He may be of that opinion but I think it was expressed in a different context at that time.
"If she is still alive out there, I'd bargain with [Lavergne]," said Shunick. "As far as I'm concerned, he can go [free] if it'd bring my daughter back, but if he's buried the body out there, I don't want to bargain for that." Quote from Tom Shunick 7/9/12 to KATC http://www.katc.com/full-coverage/searching-for-mickey-shunick/#!prettyPhoto[gallery]/90/
I agree very different from negotiating between DP and Life without Parole. And though the DA may well take the family's wishes into account to some degree when offering pleas, ultimately it's the DA's office that will determine whether they offer (or accept from defense) any negotiations.