Editor's note: Dr. Efraim Zuroff is the chief Nazi-hunter of the Simon Wiesenthal Center and Director of its Israel Office. His most recent book is "Operation Last Chance: One Man's Quest to Bring Nazi Criminals to Justice".
(CNN) -- For thirty-two years I have been actively involved in the ongoing efforts to help bring Nazi war criminals to justice -- and the most common question I am asked concerns the age of the perpetrators.
Is it still worthwhile to prosecute elderly Holocaust perpetrators?
Personally, I never doubted the validity of these efforts, but because the question is understandable and deserves a serious answer, I want to present the case for continued prosecution.
Firstly, the passage of time in no way diminishes the guilt of those who participated in the Holocaust.
Had these criminals been prosecuted decades ago, when they were far younger, the importance of the effort to bring them to justice would not have been questioned. They are just as guilty today as the day they committed their crime -- and they do not deserve a prize for eluding justice for so long.
Second, old age should not grant protection to murderers. Reaching the age of 85 or 90 does not turn a mass murderer into a Righteous Gentile. The only issue of concern is a person's mental and physical health. There is no reason to ignore someone's crimes simply because they were born in 1915 -- as was Laszlo Csatary, who at least until recently was still driving his car.
Third, every victim of the Nazis deserves that an effort be made to find the person(s) who turned them -- innocent men, women and children -- into victims, simply because they were classified as "enemies of the Third Reich." Ignoring any of the perpetrators simply because of age would be a betrayal of their victims.
The continuing pursuit of Nazi war criminals sends a powerful message about the importance of holding genocidists accountable. If we want to prevent future crimes of the scope of the Holocaust, it has to be crystal-clear that persons who commit such crimes will almost certainly be caught and punished.
Unfortunately, that has not been the case for all those who committed Holocaust crimes -- a reality which made tragedies like Cambodia, Rwanda, Bosnia and Darfur much more possible.
Lastly, the trials of Nazi war criminals and collaborators are a very powerful tool in the ongoing fight against Holocaust denial and distortion. They are an important addition to the existing documentation of the mass murders and emphasize the necessity of identifying those responsible.
In that respect, the significance of the Shoa, or the Holocaust, and the reason its lessons are so crucial for mankind is that it was not an earthquake, tsunami or volcano, but rather a manmade tragedy carried out by human beings against their fellow humans.
There are two other elements that often surface in discussing the continued prosecution of Nazi war criminals. The first concerns the issue of "superior orders" and the second relates to the question of regret.
Ever since the Nuremberg trials, international law -- created in the wake of World War II and the Holocaust -- has rejected the alibi of superior orders and emphasized individual criminal responsibility, that every individual is responsible for his or her deeds, and must bear the consequences, even if they were ordered to do so by a person with a higher rank.
Thus, Ivan (John) Demjanjuk for example, was convicted of "accessory to murder" in a German court in May 2011, for his service as an armed SS guard in the Sobibor death camp, where he was part of the group which carried out the murders under the orders of their superiors.
What of the mindset of the accused? Many people have suggested that since many years have passed since the crimes were committed, the perpetrators probably regret their misdeeds, a factor which would ostensibly weaken the rationale for prosecution.
While there may have been a few such cases of this, I have never encountered a single regretful or remorseful one in decades of dealing with dozens of Nazi murderers of many different nationalities, religions, occupations and walks of life.
If anything my experience has taught me just the opposite. Even 50 and 60 years after the events, and with so much information easily available on the Holocaust in their countries of origin and/or residence, they remain proud of the murder of so many innocent Jews and other enemies of the Third Reich.
The views expressed in this piece are solely those of Dr. Efraim Zuroff.