Murder-suicide appears to be a mass mental illness all across the U.S.

 And the problem is that it is not really predictable when or where it will happen next for a variety of reasons. It's simply a sign of the times here in the U.S. and a very serious and fatal type of mental illness plaguing our nation and more of the world each day.

Overpopulation in many animal kingdoms in the wild cause this sort of thing too where especially male lions kill all the children of the male lion they kill. Other species kill other members of their species because of overpopulation or overcrowding too when there are too many of any one species in an area.

So, this could be a biologically induced natural response to overpopulation of humans too for some human beings.

It could just be a biologically induced chemical reaction in the brain of some humans to kill others and then themselves in overpopulated areas of the world.