A thrill kill. Becoming more and more common. Just pick someone at random and kill them for kicks. There was a movie a few years ago about just such a thing. Some thugs broke into a victims home who tortured and finally killed the victim. At the end of the movie, just before they were killed, the victim asked the thugs why they were doing it. The reply was,,,”because you were home.” They just wanted to torture and kill someone for fun, and all the victims neighbors on the street were out for the night.
That is a line from a Richard Pryor routine