I think a family member of Libby's said in an interview with Websleuths that she receives a lot of "advice" from people - and something that she often is told is to tell LE to get one of the famous genetic genealogists (like CeCe Moore) involved in the case. If I remember correctly she said the ISP told her that they have their own genetic genealogy expert they are working with who does the same type of thing. I
think the interview where she talks about it is this one:
There have been other articles like this one from the Pharos Tribune where she's been pretty upfront that LE have told her there is DNA:
Family says police have DNA evidence in Delphi murders
What does it all mean, since we haven't heard about progress being made by LE on the genetic front? I don't know. But I believe things are unfolding in the case that we are not privy to.
Even if LE were able to make some solid leads through genetic genealogy, it does not necessarily mean that an arrest can happen quickly. This goes against our sense of what justice should be, unfortunately.