A few more thoughts based on personal experiences:
Some of you are questioning the husband "taking a photo" and how long that might take. I like to take photos, my partner does not. When I say, "I want to stop and take a photo," he rolls his eyes and keeps walking, because he knows that doesn't mean 1 photo, it will likely be several until I feel I've gotten the shot I want of the thing I wanted to take a photo of. And taking photos definitely pulls your attention out of the surrounding world. I've definitely stopped to take photos, while he kept walking, and by the time I'm done he's wayyyy down the trail ahead of me.
I was also reminded of a time I lost my partner for like 20 minutes in Mojave National Preserve, not that far from here on Black Canyon Rd. We had pulled over to check out a pretty cactus growing out of a rock that I wanted to photograph. My partner was walking west, towards a little rise in the land, and I went behind a rock to use the bathroom. It couldn't have been more than a minute, but when I came out he was gone. I walked up towards the rise and assumed that when I got a little higher I would see him out to the west somewhere, but when I got there it was just empty sagebrush stretching as far as I could see. I panicked -- how could he have gotten so far out of view in so short a time? I started calling his name, walked back to the car to see if he was there, nothing. Walked back to the rise, nothing. I kept pacing around, trying to think of what I would do (no cell service in most of the preserve, very seldom traffic on the road). My mind was racing to all these stories I read about people disappearing. It was only March, so the weather was nice, but he didn't have anything on him, no water, no phone, as we had just meant to go on a short walk. And he has a terrible sense of direction, so I wasn't sure he would be able to find his way back to the car if he got lost.
About that time, I happened to look south and noticed a figure in the far distance moving towards me. It was him. Apparently, he had noticed a cool looking rock formation about a quarter mile south of us and decided to check it out. He assumed I would figure out that that's where he had gone, but because I had seen him walking in a different direction first, I didn't even think to look or explore south. I directed my attention to the way I assumed he had gone, but if I hadn't, I might have seen him walking south at the beginning.
I can imagine a similar scenario here: husband continues on his path after taking photos, assuming his wife would have followed the same way back to their camper. He gets there, finds she's not there, and starts searching along the way he assumes she would have gone. But what if she saw something cool in another direction that she wanted to check out? Distances in the desert can be deceiving -- things can look closer than they are. Maybe she went in another direction towards a cool rock formation and got lost trying to find her way back. Maybe something else happened -- heat stroke, medical emergency of some kind -- that incapacitated her and left her outside of the area he expected her to be in. I understand why he wants to think it was an abduction, as at this point that would be the scenario in which she would most likely still be alive. But honestly, and sadly, I think it's more likely she got lost or incapacitated and is in the shade of a boulder somewhere nearby.
Why would she be sitting outside their camper if the key was under the rock? Why no mention that he went and searched a cave? And, a failed polygraph... Hmmm.
