The death penalty is no more. What instead?

Let’s, for the sake of this question, suppose we (all countries in the world) dismiss of the death penalty.
No matter what you think of capital punishment, you agree or disagree, what do you think would be a ‘good’ substitute for it.
For example, a person who murdered a child, normally would receive the death penalty.
What would be a punishment you be satisfied with now?

You can answer what you want, of course, but i am not looking for physical punishments, i.e. 100 strokes from the whip.