This case has stayed with me for years, although I don’t have much to contribute... Like several others posting on this thread, I was an avid hiker, although in northern New England. I hiked alone, carrying survival supplies and a concealed firearm. I had a concealed carry license for the states I hiked in. I was aware of occasional crime, mostly near trailheads, and of course there is vulnerability while hiking alone in the isolation of wilderness areas. I was always very aware of noise, color anomalies, and potential hiding places. The only real danger I ever encountered was a bear, but that incident ended without any harm to either myself or the bear.
I will say one thing about David Stodden returning to hike with his other daughters. I think it is way to reclaim the joy that he and other family members experienced in nature. During one hike I made years ago, I sprained an ankle just below the top of a mountain summit. I bound it up and made it back to the trailhead with a metal staff/pole I used for support. I drove myself to a hospital, and my ankle was swollen and sore for a while. But the following year, I actually returned to this trail. I didn’t want this bad experience to ruin my enjoyment of hiking, so I went and completed the same hike where I’d had the accident.
Mountain trails can be full of ambush points and areas where a predator can ambush someone. If 2 people are hiking and talking, they could be distracted and unaware of sounds that could signal a problem, such as the sound of crushing leaves or another person’s breathing.
Israel Keyes comes to mind for this crime. His timeline may or may not fit, but I think the murders were perpetrated by an opportunistic predator. Such an individual may have been in the area with the intent to commit a crime, and the mother and daughter appeared. I hope there’s some DNA that will eventually identify the perpetrator.