the family is cooperating at this point with whatever the investigation requires. I will agree I imagine they are very concerned because some of the things they were going for implied that Justine has committed the crime. I suspect they will keep quiet until they see if Noor will be charged...if not I too as a family member would take further legal action.
TBH, the moment they start "investigating" reasons why he may have pulled the trigger, as a family member, I'd likely grab me a lawyer and keep my mouth shut. They are going to use everything that family says against the victim. Ugh.