I think a lot of controversies in statements given are suggestive of: 1. The family is trying to cover up something they know and a part of directly or indirectly, without realizing how contradictory their own statements are. 2. Attempt by defense lawyers to create a loophole stating, they are not in a proper state of mind to give statements.
Whether the family is a part of crime or no, they have to answer many a questions, as many have already mentioned.
If the family does not know anything, it is suggestive of a totally disfunct family.
