The recent conviction of a 93-year-old Auschwitz guard reignited a debate about prosecuting the remaining few Nazi war criminals. Most observers call for a no-holds-barred hunt for the Holocaust perpetrators who have evaded justice for decades, but others point to their old age, legal issues and difficulty in proving the crimes, arguing that after nearly 80 years, the pursuit should come to a conclusion.

In the most recent case, German prosecutors charged Oskar Gröning, a former SS member, with at least 300,000 counts of accessory to murder while he was stationed at the Auschwitz concentration camp. Mr. Gröning, known as the “accountant of Auschwitz,” collected money from the luggage of newly arrived prisoners, which he would then turn over to the SS headquarters in Berlin, The Wall Street Journal reports.

The Gröning case is among 30 others, all against former Auschwitz-Birkenau guards, a result of a wide investigative push announced by German war-crime prosecutors in April.Whether they will be put on the stand depends on the investigation’s results and on the health of the accused.

The precedent for the latest action came in 2011 with the conviction in a German court of John Demjanjuk, a former Sobibor death camp guard, who was found guilty on charges of accessory to murder. Being a guard with no direct involvement in the killings, the court ruled, was sufficient reason for conviction.

“My personal opinion is that in view of the monstrosity of these crimes, one owes it to the survivors and the victims not to simply say ‘a certain time has passed, it should be swept under the carpet,’” Kurt Schrimm, the special prosecutor who is leading the renewed effort to bring the Nazi criminals to justice, told Der Spiegel last year.

Thomas Walter represents 20 Auschwitz victims and their families in the case. He said that it’s the victims’ last chance “to bring justice to one of the SS men who had a part in the murder of their closest relatives.” He added that many of them are among the last survivors of the infamous camp.

But some experts point to legal issues related to the Demjanjuk precedent.

Christoph Safferling, a criminal law professor at the Philipps University of Marburg, told The Wall Street Journal that the case “brought a loosening of established law practice” because the crime lies in having worked as a guard and not a specific act directly involving the accused in the killings.

Others argue, however, that the definition of a crime should be broadened in the case of the Holocaust. For now, according to German law, “just participating in the Holocaust doesn’t count,” the law professor Ingo Müller told The Guardian. And that, he says, is a historical failure, as past efforts to convict SS members have failed precisely because of this narrow legal basis.

“We can’t just let it stand that the German judiciary says participating in the Holocaust is not a crime,” Mr. Müller says. “If two or three more people were to be convicted — they don’t actually have to go to prison, they can stay in their old people’s homes — it would have a symbolic effect.”

This debate comes as part of a continuing discussion about prosecuting the aging participants in the Holocaust.  

“The advanced age of the often frail suspects has brought forth sympathy among some in Germany, raising questions of whether it is just to pursue prosecutions now after having let them live out so many years in peace,” Melissa Eddy writes for The New York Times.  But the general sentiment in the country, Ms. Eddy writes, is that Nazi crimes are “better pursued late than never.”

Outside of Germany, the most vocal advocate for prosecuting Nazi crimes is Efraim Zuroff, known as the world’s last “Nazi hunter.”

Mr. Zuroff called the Gröning charges “very good news” and told The Jerusalem Post that “it is unfortunate that this proactive approach has only been applied so many years after the end of World War II.”

In a 2012 op-ed for CNN, Mr. Zuroff emphasizes that the passage of time does not diminish Nazi criminals’ guilt. “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.”

He also says that hunting down Holocaust perpetrators is a warning and a lesson. “It has to be crystal-clear that persons who commit such crimes will almost certainly be caught and punished,” Mr. Zuroff says. He adds that it’s also an important component of the fight against Holocaust denial.

In her profile of Mr. Zuroff for Foreign Policy magazine, Katie Engelhart cites several experts who disagree with the famous Nazi hunter. The historian Michael Marrus told Ms. Engelhart that he is concerned that the proceedings aim to “close the chapter” of history, which should not be the role of any court.

Guy Walters, the author of “Hunting Evil,” told Foreign Policy that part of the problem with the hunt for Nazis is that “it becomes a very bipolar moral universe.” He worries that the story that emerges from the trials shows that everyone engaged in Germany’s World War II machine is a war criminal, regardless of individual circumstances.

Mr. Gröning has defended himself in that vein in the past. He said that calling him an “accomplice” would be “almost too much,” and described his role as “a small cog in the gears” in a 2005 Der Spiegel interview. “If you can describe that as guilt, then I am guilty, but not voluntarily. Legally speaking, I am innocent.”

The question remains — should these people, “cogs” or not, be brought to justice?

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