Good point. The more I think about it the more that seems logical.
Was clothing removed after she was killed or before? Clothes in the water would still probably be stained.
Sadly, I think this may mean that they were disrobed before being killed. But how would he have done that without having to restrain at least one of them?
I always thought they would find handcuffs, zip ties or duct tape but none of that... so he must have had a gun on one of then then forced the other to take off their clothes. Maybe one at a time then reverse.
But how did Abby end up with Libby's clothes? I mean it is hard to redress someone even if you put baggy clothes on them from another person. Did he kill them then try to redress Libby, which was too hard to do and then just did Abby with Libby's clothes.. .then threw all the other clothes in the creek?
Not that this matters, by whomever did this is one very disturbed person.