Civil society must deal with miscreants up to keeping unrepentant dangerous behind bars in protection of society. But the death penalty is not now in the “justice” equation. It is only in the unjust “vengeance” equation.
I respectfully disagree. Murderers are capable of calculation, and empirical evidence shows that the death penalty absolutely deters murder.
New York used to have a “three strikes and you’re out” law, which made the third violent felony conviction an automatic life sentence. Someone twice convicted of robbery had little incentive not to kill his next victim, and a great deal of incentive to do so. The only disincentive is the realization that the police might investigate a murder more vigorously than a robbery.