I'd tell the family that they need to seek closure somewhere else than in vengeance, because the closure vengeance brings them corrupts more than it heals.
Übereil
That's a nice sentiment but sadly it sounds like pacifism. How does vengeance breed corruption? I'm curious so don't feel offended.
Let me just sum it up this for my final post on this topic-
The American justice system, like most of those in at least the Western world, is built on an idea called retributive justice. In very simplified terms (sorry, I'm not a legal scholar), it defines justice as appropriately punishing someone for an act that's harmful to society.
Our system does include other ideas: incapacitating a criminal from committing other crimes, rehabilitating criminals to rejoin society, and deterring other potential criminals. At its foundation, though, retributive justice is about enforcing both rule of law and more abstract ideas of fairness and morality. Crimes are measured by their damage to society, and it's society that, working through the court system, metes out in-turn punishment.
Justice is treated as valuable and important in itself, not just for its deterrence or incapacitative effects. In a retributive system, the punishment fits the crime, and 21 years in a three-room cell doesn't come close to fitting Breivik's 77 premeditated murders.
Now the Norwegian-style restorative justice subverts those human desires for justice and fairness, which does seem to have found success in reducing crime's cost to society. Proponents, such as University of Oslo professor Thomas Mathiesen, say it's better for society overall because it isn't about "revenge, but sober, dignified treatment."
But is the retributive-style need for justice and fairness really only about "revenge," or is it something more important than that? The retributive approach absolutely has its pitfalls — the American system's heavy emphasis on punishment has a history of leading it to horrific excess and abuse — but at least it's meant to be just.
I don't know how you balance that against the overall social good, which Norway's gentler system seems to have found success in promoting, but the vastly different philosophies of the two systems are a reminder that, even if right and wrong are universal, how society treats them is not.