I do feel badly for Anita van der Sloot because I think that she is an innocent here. (With the exception that she assisted in raising an out-of-control man-child.) My feeling since very early on is that her son is guilty of a Robert Chambers type scenario, and that her husband helped him to cover it up in some way. (Probably assisting in disposing of the body at sea.)
Obviously, purely my two cents.
PVDS may have advised on how to cover-up.