Six very tragic events. The ATC estimates that about 12,000 folks have hike the entire trail. That makes a murder rate of about 0.5% - compared with the 4.8% rate for the entire country. There have been other murders on the trail that didn't involve thru hikers but then our statistics need to include total number of section and day hikers which probably (just my guess) hovers around the same as the murder rate for thru hikers. If I lived in a country where the murder rate was 0.5%, I'd feel pretty safe. I think ultimately it depends on the person - some folks never feel safe and statistically rare incidents like this only tend to reinforce that bias.