After seeing the area in the video I'm really puzzled over this. I can understand how they crossed the water but not why. And yes, I realize it's something that only the murderer(s) can answer but it does make me wonder if there was some sort of significance to that spot. Both sides of the river are secluded so it probably wasn't for privacy. I just don't know. Maybe they did it to intimidate the girls psychologically or maybe they felt it would be harder for the girls to run.
Ugh. Whatever the reason, my heart aches when I think of the terror Abigail and Liberty felt.