I also suspect the Aungs are involved but 2nd guess that when I remember the FBI is also involved.
If the Aungs were involved, after 4+ weeks of this investigation LE would already know exactly how, and likely would have arrested them by now for their part in this felony as well as located their son, NC and the baby.
Of course cases can drag out for months and years without an arrest but that's almost always when a huge part of the puzzle is also missing from LE. The Aungs aren't criminal masterminds (and neither are AA or NC) hiding anything from LE, so that makes me think that part of what's missing is that they aren't as involved as I'd guess most of us assumed. Maybe.