I am deeply suspicious of the concept of closure. The general public and policy-makers take it as an article of faith that there is something called closure that the criminal justice system can help provide. Even Dalia Lithwick takes it more or less for granted that closure is real. She just questions whether executions are the best way to help survivors achieve it.
Intuitively, we all know more or less what closure is supposed to be. At first grief is overwhelming and all-consuming, but eventually it fades enough for the bereaved person to get on with life. Closure has something to do with that transition.
Upon closer examination, the concept of closure turns out to be much more elusive that we might have supposed.
Closure might refer the emotional shift from acute grief to emotional healing. Alternatively, might to describe some psychological or practical prerequisites that must be in place in order for a person to transcend acute grief (e.g., time, insight, restitution…).