killing of innocents

Suppose you have killed your daughter and son in law and went to jail. You have spoiled your own life and will suffer long term pains.If they love each other and want to live their own life peacefully.It indicates that we are living in BARBARIC AGE.Parents and society have no power to humiliate them.Every soul is Independence to enjoy with in limits.NOW what will be the fate of killers,they have to pass their life in jail.Sentence of jail is not sufficient, they should hanged till death.