Yeah, that's the part that gets you the most in both videos. Their complete lack of respect for another as a human being. It makes you so disgusted to think there are other humans who are like this and sharing the planet with us. You just sort of used to think that humans had some level of respect and decency, until these scum came along.
What I found the most disgusting is how they made both victims submit to the killing apparently naked wrapped in some kind of tarp. They are completely aware of the terror they are about to induce in another person and they plan for it. They are completely sick and inhuman.