I don't quite understand the question, so I will simply provide my rationale for not taking my eyes off this man in both Julia and Chelsea's case.
We know he has been arrested for allegedly possessing child *advertiser censored*. That case is pending. In addition, he is a POI in his stepdaughter's murder because allegedly he has not provided LE with satisfactory information as to his whereabouts leading up to, and on the night of her murder.
The Niswender and Bruck girls were/are friends. One of them was just in the others wedding recently. There is history there. It is natural to examine both cases for any linkage beyond the obvious.
My hypothesis is that both Julia and Chelsea were silenced for something they mutually had knowledge of, directly or unwittingly. Perhaps they themselves had been victims of a predator during childhood, unbeknownst to their mothers. I would suggest both mothers reflect on any recollections of major and inexplicable changes in behavior, sudden onset bedwetting beyond a reasonable age, etc. I'm sorry to say all this, because I'm sure it's horribly upsetting at many levels, but I think it should be considered, and hopefully dismissed quickly.
These are my thoughts at the moment. All speculation only. I am highly confident that LE is examining all of these possibilities closely.