Again, there is NO better way to protect society against repeat offenses by a convicted criminal than to kill said criminal. If protecting society is the goal then we should be killing more criminals, not fewer.
I believe in the God-given sanctity and right to life and so does God who knew man would fail, so He Himself took the hit for everyone including that criminal. So even if the criminal takes other lives, God himself has paid for his crimes so the dangerous criminal is not condemned. His right to live has been purchased howbeit away from people on the outside who also have a right to live. So the criminal's right to life stays intact although his right to freedom has been curtailed to protect the lives of others.