So much for that folk lore. Even better chimps conduct war. Thus it turns out that same species murder is more the way things are than any particular exception. And we are only typical for primates. It was obviously time this idea was tested rigorously.
I do believe that we can develop a society in which murder completely disappears. It is obviously desirable. That will not heal those who are bent, but the likelihood of being bent should decline sharply and even converge to zero.
Nature in tooth and claw has meant infanticide often by a new male who truly gets the opportunity to kill off an absent rival's offspring.