I don't think they've ever said they weren't any closer to solving this as they were on day one (as far as I recall anyway)... although, until they arrested DM, I've been very inclined to believe they mostly have nothing.
DM could be a red herring, but he also has the potential to be a big break in that he seemingly fits the profile of someone who would abduct and kill a young woman. And has now done it from the same general area. Of course we don't know how random this really was or what led up to this.
But prior to this I think LE has mostly been befuddled. We've seen no real activity in the case in quite some time. There have been no leaks of substance. For 5N to be guilty as a group you are asking a lot of college kids to so successfully pull off a crime of this nature. As I've always said, with the general theories that paint them as guilty you have a ground zero where the crime occurred. Which means LE knew exactly where to look for forensic evidence. They also knew where to look for security footage of their vehicles, track their cell phones, etc and under a narrow window of time that would matter. And you had multiple people that not only needed to keep their story straight but not crack under pressure (be it internal or external pressure).
They might've found something and be holding it close to their vest, but it clearly isn't enough they feel they can act upon it.
With JW considered, you need to be able to break his alibi and then connect him and LS that morning. It begins to add randomness to the scenario because there's no longer a ground zero with which the crime took place. But it also means LE should be able to track his movements that morning as well. You'd think anything unusual in any of their movements would be the leverage LE needs.
Now we have DM in the picture. Once again, there is the randomness of the crime scene in this scenario so that LE never had a particular ground zero to search for forensic evidence. You wouldn't think this guy was even on their radar at all back then.
So here we are with questions and no answers. At this point I think it's pretty obvious LE doesn't want the public's help. As the former FBI agent said in so many words, they've been very tight lipped. While it's clear they wouldn't want to jeopardize their case, I think it's good to ask "What case?".
Personally, I don't think this case is going to involve theories that tie several people together. There's not going to be low level dealers and high level drug lords called in to 'handle' anything. There are not going to be college kids blackmailing other college kids to maintain a story. The more complicated the conspiracy, the more easily unraveled it would be. At best, IMHO, you might have some people wondering about another's potential involvement but not willing to bring themself to actually say it out loud for fear they are just letting their mind run wild. Of course these are the kind of people that might talk if LE laid some cards on the table and laid out a theory or a couple of scenarios. Maybe learning their nagging suspicion actually made sense in light of some evidence, statement, or official theory would cause them to come forward once they realize they have something that might be relevant after all.
So we're back to 'why' is law enforcement so quiet. Obviously, having absolutely nothing could be one reason. But then you'd think that could also be a reason to come forward at this point just to update timelines and re-balance the narrative and talk about the bar witness statement, etc.. Of course, having the case all but figured out, but lacking the smoking gun, is another possibility. But there again, at some point you'd think they'd want to stir things up to try and shake that smoking gun loose.
I suppose the reason could be political in nature. Maybe nothing found really pointed towards the known PsOI but there was a decision made that it be better to let public suspicion look that way versus admit to the possibility there is a random abductor/serial killer loose in Bloomington stalking college hangouts. That wouldn't be good for IU enrollment.
And I'm sure there are other possible reasons stretching from preserving the development of case for trial to a fault, to extreme competence (know exactly what they are doing and are playing it perfectly for the endgame), to incompetence.
