Well, one sighting, anyway. LE said it was a neighbor that had a Q&A with Lucas, a VI here said it was the land lord. It could just be one person.
Also, who's to say, after EG's ex picked up the boys on the 11th, that something didn't happen that night? Would she be sick enough to keep him in the bathtub for a few days (yes, people have done this, a recent case here on WS had a man who shot and killed his friend and kept him in the bathtub for over a week until HE called LE!), before placing his body in that culvert?