What Say Kopechne

I have a question that some enterprising pajama journalist might investigate and answer. Why was there total silence from the Kopechne family after there daughters death?. There were no criminal charges against Teddy at the time (other then, but there were never any civil procedings instigated either. Not a word from Mary Jo's family. Were they payed off? "Camelot" may have prevented it then but there is no reason it can't be investiagted now. Thoughts?