Crime, like charity, begins at home, and home is therefore the first line of defense against crime.
A second line of defense is necessary and — in these times — essential to the general welfare. That line of defense is justice, administered by the community through the state.
The linch-pin of justice is punishment by law. The operative word is “punishment” — not “correction” or rehabilitation.” Crime is not deterred or prevented by the promise of rehabilitation. (Who commits a crime in the hope or fear of being rehabilitated?)
What if deterrence does not always work, as those who are opposed to capital punishment like to point out? For sociopaths and psychopaths who are undeterred by the concept of punishment, the answer is punishment of a kind that will ensure that they can no longer do harm to others: life in prison or death at the hands of the state.
There are those who equate death at the hands of the state with murder. This is nonsense and sentimental clap-trap on a par with counseling unilateral disarmament or pacifism in the face of an invading horde. By such reasoning, we would not have (finally) risen to the task of removing Herr Hitler from the scene. How many sob-sisters (of whatever gender) would wish that we had stayed on the sidelines while Hitler applied the “final solution”?
Justice — when served — serves civilization and social solidarity. First, of course, it deters and prevents wrong-doing. Second, it meets the deep, common need for catharsis through vengeance, while protecting the innocent (and all of us) by replacing mob rule with due process of law.