I'm feeling pessimistic and I don't think anything will happen fast.
The sheriff briefed the family before the search on the docks and they may have had faith that they could find her remains there but it was said they didn't find human remains. If they don't have a body it is much harder to build a case when all you have are several persons of interest who are all telling a different story each time you talk to them. They may eventually, but the way I see it now, if they charge all of them together the defence can say, we just made it up to get out of the drug charges, or because of police pressure, we were forced to confess, and it's not a real confession, look at how the stories don't even line up, and you didn't find a body there so it proves it was a made up detail. If they charge Misty alone, her defence is going to point at Tommy and Joe and say, there is reasonable doubt it wasn't Misty. If they charge Joe, his lawyer will point at Misty and Tommy. If they charge Tommy, his defence will point at Misty and Joe. If they charge anybody else his/her defence is going to point at all three of them and say these people said they were there, why are you looking at my client? The circumstantial evidence had better be airtight to convict.
Anyway, if it's Misty, Tommy, or Ronald that they're going to charge there's no hurry, none of them are going anywhere. If it's Joe or someone else at large there might be a risk of reoffending and it would be a more urgent matter.