He doesn't have to be hiding anything. He has a lawyer whose job is to get the best possible outcome for Ron, which would include putting the people who killed his daughter in jail and spending as little time in prison as possible. If LE was offering a plea deal, he would have been stupid to turn it down, given the potential 90-year sentence for selling a few hundred pills. Really, if LE has eliminated him as a suspect in Haleigh's murder, then I can't see a reason in the world for him to do life in prison. And as long as he testifies, and her killers go to prison and stay there, that's the best that we can hope for now. There is no contradiction between wanting justice for his daughter and allowing his lawyer to negotiate the best terms on the drug sentence (and perhaps immunity from prosecution if he has to discuss other crimes while testifying against Misty--e.g., other drug sales, etc.). Ron after all has TWO children. Why would we hope that he just abandons Junior and makes no attempt to salvage some opportunity to be a father to him? Ron has a responsibility to fight for as much of his own life as he can get. The great irony here is that, at last, Ron Cummings is working inside the system, taking his consequences, following the legal process, going to prison without complaint--and still that isn't enough. He's the only human in American who shouldn't take an offered plea deal because the public thinks he should pay for supposedly putting a rat in a mailbox? Marrying Misty? Who does life in prison for that kind of stuff?
Ron is not a suspect in Haleigh's murder. The people who are suspects are pointing the finger at each other. If he isn't a suspect, he's a victim, and I for one think he is already enduring the worst possible punishment for his immaturity, arrogance and bad choices. But whatever he did or didn't do, Ron did not invite people into his home to assault, kidnap and murder his daughter. That puts him into a very different category from those who attacked a little girl in her own bed and dumped her in a river or landfill or whatever story the Croslins are peddling today.