According to JD Walters:
But what if the following conditions held: suppose the perpetrators of genocide were to become fully aware of the enormity of their crimes and were overwhelmed with remorse (again not just because they were caught but because they realized how deeply they wronged and violated their victims), all the hurt and suffering of the victims were completely erased so that the dead came back to life and wounds healed, including their memories so that they did not even remember the pain and anguish of their persecution, and a new society appeared in which it would be impossible for any further abuses to take place? Would we still demand that the perpetrators suffer?...In such a condition, the only compensation that those who lose a loved one to murder can get is the satisfaction of knowing that the murderer is being punished. And in order to maintain its authority, the state has no choice but to uphold the law and mete out punishment. Note however that this is only partial compensation: it is not justice, because the loved one is still dead, and the murderer may still be unrepentant. True justice would be for things to be made right: the dead loved one restored to life, and the murderer repentant.
Suppose a mad scientist kidnaps children and tortures them to death. Every time he tortures them to death, he feels sorry for his crime. Every time he dismembers them, he weeps.
So he brings them back to life, repairs the physical damage, and erases their memories of the ordeal. Then he repeats the cycle ad infinitum.
Is the fact that he restores the status quo ante each time true justice? Is the fact that he feels bad about his crime true justice?