Mysterious disappearances explained?

For those of you that care, we finally figured out what these strings of disappearances are. We found a set of corpses at an abandoned school. One was hanged, two were poisoned, and three were shot. They were identified as all related to each other; six members of the same family. They had histories of violence towards one another in the past. It seems they all came here to finish their arguments once and for all, and killed each other. The only strange thing is the other six people who disappeared last week. They too have a history of violence towards one another. However, it would be odd for both to be isolated incidents; the disappearances are too similar. I will update when I get more information.