You can't hide from justice forever—not even for war crimes committed decades in the past, and not even when you're 93.

That message resounded loudly this week as Germany announced the arrest of Hans Lipschis, age 93, for complicity in mass murders that took place at the notorious Nazi death camp of Auschwitz-Birkenau, where he served as a guard in 1941-1945. Lipschis—who says he worked as a cook at Auschwitz—is the first to be charged from among a list of 50 former Auschwitz guards that the country's Central Office of the Judicial Authorities for the Investigation of National Socialist Crimes plans to probe.

The Demjanjuk Precedent

Why go after them now, 68 years after the end of World War II? Because it was not always possible to do so in the past. In 2011, the conviction in Germany of Ukrainian-born John Demjanjuk, who had served as a guard at the Sobibor death camp in Poland, set a legal precedent for interpreting evidence more broadly than before. Until then, German prosecutors essentially had to prove that a suspect had committed specific crimes against specific victims at a particular time and date, and such direct evidence against camp guards was difficult to produce.

Demjanjuk's conviction—in which his SS identity card from Sobibor played a major role—"was a game-changer because it allows for the prosecution of people who would otherwise not have been prosecuted," said Efraim Zuroff, the Chief Nazi Hunter for the Simon Wiesenthal Center, a global Jewish human rights organization whose mission includes confronting anti-Semitism and promoting tolerance.

As a result of the Demjanjuk precedent, guards who worked at death camps could be charged with abetting, contributing to, or being complicit in the killings that took place there.

Lipschis is an example. "We don't know if Lipschis personally murdered anyone, but he served at Auschwitz for almost the entire time that the camp was in existence," Zuroff said. Lipschis had lived in Chicago since the 1950s, but was deported from the United States in 1983 for falsifying his past as a Nazi. Of the 50 former guards being sought for investigation in Germany, Lipschis was the only one to also appear on the SWC's 2013 Most Wanted Nazi War Criminals list.

Number One on the List

The highly dubious "honor" of being number one on the SWC list goes to Laszlo Csatary, now 98. While serving as a senior police officer in Hungarian-occupied Slovakia in 1944, he organized the deportation of approximately 15,700 Jews to the Auschwitz death camp. In 1948, a Czechoslovak court convicted and sentenced him to death in absentia.

Csatary eluded authorities, fleeing Europe for Canada. He worked there as an art dealer until 1997, when Canadian authorities found out he had lied on his passport application and revoked his citizenship. He did not surface again until 2011, when he was spotted in Budapest, Hungary, as the result of a tip received by Operation Last Chance, a joint project of the SWC and the Tagum Shlishi Foundation of Miami. He awaits possible prosecution in Hungary, where he is currently under house arrest, or—if he is extradited—in Slovakia. "Until we exposed him, he was driving his own car," said Zuroff.

Second on the SWC list is Gerhard Sommer, a former SS-Untersturmfuehrer in the 16th Panzergrenadier Division Reichsfuehrer-SS, who was convicted in absentia in 2005 by a military court in La Spezia, Italy, for participating in the 1944 massacre of 560 civilians in Sant'Anna di Stazzema. No criminal charges have as yet been brought in Germany, where Sommer now lives in a nursing home. "We're not that optimistic" about his being brought to justice, said Zuroff, "because he has been under investigation for several years, but so far there has been no progress in prosecuting him."

Vladimir Katriuk is third on the SWC list, which describes him as having served as a platoon commander of a Ukranian battalion that "carried out the murder of Jews and innocent civilians in various places in Belarus."

Like Csatary, Katriuk managed to emigrate to Canada after the war. He gained citizenship and was reported to have been a beekeeper and a prominent member of his local Orthodox Church. Although his citizenship was revoked in 1999 after his Nazi collaboration became known, the decision was overturned in 2007. Since then, however, new evidence has come to light about Katriuk's role in the mass murder of the residents of Khatyn, Belarus.

Why Age Is Not a Factor

Even though most of those on both lists are now in their late 80s or 90s, their age is no reason to stop seeking justice, said Zuroff, who is the author of Operation Last Chance: One Man's Quest to Bring Nazi Criminals to Justice. "Don't look at these people and say they look frail and weak. Think of someone who at the height of his powers devoted his energies to murdering men, women, and children."

He added: "The passage of time in no way diminishes the guilt of the killers. Old age should not provide protection. The fact that they have reached an elderly age does not turn them into righteous gentiles."