If I was guessing and I am admittedly have limited information I would guess a syringe with a rather fast acting agent. If that turns out to be true it almost had to be voluntary on the part of at least one of the adults. No outward sign of trauma is being reported. I could see 1 of the adults sneaking an injection into the other or both being in on it but it's pretty improbable a stranger could have done it. And how would you find a friendly third party to assist. I'm sure they are looking into their internet searches and their finances. Hopefully there are investigators thinking outside the box and digging. I did law enforcement out in the boondocks for 30 years and there is certainly some strange stuff goes on out there. I always said that when you found someone out on the National Forest roaming around at 2AM that poaching was probably the nicest thing they could be up to.
Patriotism (and religion) is the last refuge of a scoundrel.
