Murder in the Family
Familicide, or the killing of one's own family members, especially your spouse, progeny, or parents, has always been viewed poorly in most societies, though in some cases there were exceptions.
For instance, in Ancient Greece and Rome the practice of leaving a newborn child to die of exposure if they were born physically deformed
was considered perfectly acceptable
. It has also served as a method of gaining greater power via getting rid of competition, or for conserving resources in extreme cases during hard times (if the bodies didn't also end up becoming
Obviously, this is a sub-trope of Domestic Abuse
, and is the most extreme version of it. For other (non-lethal/violent) instances of family tension, see the Dysfunctional Family Index