A skull from 430,000 years ago shows evidence of murder with a blunt object.

The cave where 28 skeletons were found also shows evidence of funeral practices.

This does not surprise me, since humans kill each other, and so do chimpanzees. In the case of chimpanzees, it is typically a group that does the killing, and that is common for humans too. It seems plausible that the common ancestor of the two species did this also.

However, the different example of bonobos show that another way exists.