did not the solicitor say in court that they don't believe Heathers purse or phone or whatever won't be found in the river? that they did searches, sonar etc...they found nothing and don't believe her belongings will ever be found there
so they really can't say she was killed there...they are really guessing...imo she was somehow disabled there ... hit over the head with something, strangled...then placed in the truck...
but during an interview that TE did with PH (you can snip this mods) TE stated that for the first 20 minutes it was thought that this was a runaway or something like that, but after that the PO felt it "abundantly clear" that something bad happened to heather...
ETA: i think the solicitor info came from hoppy who was in the courtroom today, if not hoppy, IAIA