I just find it highly unlikely that Mr. Shephard has a direct line to LE or that they are choosing him, of all people, to share the fruits of their investigative analysis with.
If I recall, the parents have stated on a couple of occasions that they do NOT think someone could have entered through that window.
I would not be surprised if Fox has a direct line to LE considering they have been reporting locally on the case for days now.
The parents raised the possibility of the open window as point of entrance/exit and LE have explored the validity of that possibility. After all, if either parent is going to prosecuted, their defense team would raise it at trial as a possibility that LE ignored. LE are doing their job.
JMO