One advantage of having closure is that it greatly reduces the challenges the victim faces going forward.
Some of those reductions in challenges are warranted. Some of those reductions are not.
We, as a society, endorse the concept of innocent victimization: if someone is made to suffer at the hands of another, the sufferer ought not have any further social obligation. For the most part, that's fair.
However, life can never be made completely fair, and I argue it should not be. If such were the case, we would not require any higher level of mental functioning than simple seeking and avoidance behaviors. There would be no point to sophisticated problem-solving, as there would be no complex problems that needed solving. Natural selection seems to favor some species developing higher skills of reasoning, which could indicate that this is an expected consequence of our form of life in our environment. Genetics also provides little incentive to reduce gradual increases in complexity that aren't strictly necessary; indeed, one of the resultant characteristics of this is diversity of life, which as a whole seems to promote the continuance of life in general in an ever-changing environment.
I cannot pretend to empathize with most of the suffering in the world, particularly the more severe forms, but I can say that personally, most of the suffering I have experienced has been challenges providing opportunities for personal growth. I did not always see things this way. I do not want this to read as an endorsement of mild forms of suffering, but merely as a reason to not try to eliminate completely nor balance absolutely the unfairness inherent in the human condition.
There is something to be said for the psychological benefit of having some degree of closure. I do not believe lawmakers should try to enforce the maximum possible closure. I favor the idea of rehabilitation of criminals; in the cases where re-entry to society would be irreducably dangerous, such as strong cases of sociopathy or impaired functioning resulting from traumatic brain injury or genetic predisposition, I would tend to favor restrictions of mobility and physical functioning only as necessary to prevent most of the possible social damage. These restrictions would, to the extent possible, scale inversely with the level to which a criminal seeks to maximize their benefit to society.
Note that, by rehabilitation, I do not wish to imply sudden and unsupervised social re-entry. Rehabilitation is a tricky game that human culture has only begun to play with a modest level of success.
In other words, closure oughtn't be absolute, rehabilitation should be sought when possible, and where it is not possible, an individual's pursuit to integrate with society should influence the degree of their confinement.
Of course, this could all be a crock of shit. I haven't done any deep research into the statistics of recidivism to support my point of view.