Any death where the killer and victim are related by blood.

Storytellers have always been fond of tales which involve deadly nepotism.
Patricide, Matricide, Fratricide, Sororicide, Filicide - human history is filled with examples of them all, so it is no surprise that Hollywood is as well.

The icon for this category is supposed to be a family tree - hey, it looked OK until we shrunk it down!