Can the killing of a human being by another be justified?

Only when a human being tries to kill another human being, can the human being be killed. For no other sin should a human being be killed by another human being. This applies even to all living beings. You should not kill any living being when it is not going to kill you. The punishment of death should be given only to the crime of murder. The crime should have the punishment of the same level. Every sin is given a punishment of its own level. The Dharma Shastras reveal various punishments for various crimes. All this is Pravritti, which means the field of behavior of a human being with other living beings. Rama taught Pravritti. Nivritti means worshipping the Lord in human form. Krishna represents Nivritti. One should concentrate on Nivritti, which alone can give the salvation. If the bonds with your family members and even the bond with your body and life are cut, Pravritti disappears. The aim of the human life is Nivritti and not Pravritti. One should not waste the time in Pravritti.