From the RTV6 story four months after the murders, discussing why more information is not released to the public about the crime scene:
"Sgt. Holeman says it is difficult for someone outside of the investigation to see, but there is a reason for the limited public information.
'We use this term a lot – we have to protect the integrity of the investigation,' said Sgt. Holeman. 'Whoever did this is probably the only person who knows some of the details of this case.'
That’s because the hardest part of this case isn’t going to be arresting a suspect – it’s going to be proving, without a reasonable doubt, that that person is responsible for the crime, so they won’t be set free based on lack of evidence."
First, law enforcement are the experts, not me. And Delphi LE have received FBI help so I doubt they are just "small town bungling" their way through the investigation and release of information.
However, the scenario Sgt. Holeman referred to above would only be true if the investigation had homed in on a family member. It would NOT be true if this turns out to be a stranger abduction/murder.
Why? Because DNA evidence at the scene, if it matches any member of the family or extended family, could be explained away or justified. But DNA evidence from a stranger on either of the girls would not be. In that event, the hardest part of the case is identifying a stranger-suspect whose DNA is not contained in a database due to a prior felony conviction.
It is possible that LE spent the first few months focusing on (or trying to clear) family or extended family. The downside to that approach is that these types of cases, with two murders in a public location with girls from two different families, are far more often a crime of opportunity for a predator than a family member. And in that case, getting information out to the public to identify a suspect is more important than worrying about proving the eventual suspect guilty beyond a reasonable doubt in court.
This is why I think the case will mostly likely break only if (1) more information is released to the public and a tipster phones in (like in the Brianna Denison case); or (2) more DNA samples from the public are provided online and a connection is established to the killer's extended family.