I think it is a little odd that LE either didn't see 54 barrels in May, or that at least one of them didn't have the same suspicion many here instantly jumped to:great place to hide another body or evidence. Once they found TB at the farm they didn't just pack up and leave, saying, 'Well, the warrant was only to search for a body, we can't get out our microscopes yet.' In my opinion they would have likely had permission in that warrant to continue looking for say, blood splatter or a murder weapon, or further victims. Which would make me wonder why they didn't look under they hay or in the barrels the first time.
If, as some suggest, they were waiting for lab results for further warrants to continue their search of the barn, I believe that they would have put up at least some crime scene tape warning the public not to cross it. Wouldn't that be cheaper and easier than hidden cameras? I would think hidden cameras would only be used if LE strongly suspected the third suspect would return after they were gone, to tamper with evidence. But I think that even in that situation that they would have put up some tape, so that they could prove that it was in fact still a crime scene that was being tampered with.