At the start of May, 93-year-old Hans Lipschis was arrested in the German state of Baden-Württemberg. Lipschis is a former guard at the Nazi extermination camp in Auschwitz who lived virtually undisturbed for decades after the Second World War in Germany, and then in the US between 1956 and 1983.

His name was recently fourth on the list of the top 10 most wanted Nazi war criminals of the Simon Wiesenthal centre. Born Antanas Lipsys in Lithuania in 1919, he worked as a guard at Auschwitz between 1941 and the beginning of 1945. In this function he was instrumental in the murders of thousands of overwhelmingly Jewish prisoners. The state prosecutor in Stuttgart released this information as the reason for the arrest.

Antanas Lipsys joined the SS in 1941 and became a member of the sixth company of the SS-Totenkopf Sturmbann (death head unit). He was granted German citizenship in 1943 under the name Hans Lipschis. The main task of the “death head units” was the supervision and administration of the concentration camps. They were responsible for the smooth running of the Nazi regime’s mass extermination machine.

As with tens of thousands of Nazi henchman and collaborators, Lipschis was able to cover up his crimes in the SS and live at first undisturbed in the German Federal Republic after the war. In 1956, he emigrated with his wife and two children to the US. When his previous activities as a guard in a concentration camp were uncovered, he was deported in 1983. Since then, he has lived untroubled by the German authorities in Baden-Württemberg.

The background to the arrest of Lipschis was the trial of a former guard in the Sobibor concentration camp, John Demjanjuk. Demjanjuk was sentenced to five years imprisonment two years ago by a Munich court for accessory to murder in the case of more than 28,000 Jews in occupied Poland.

The conviction of Demjanjuk, whose appeal was never heard by the constitutional court due to his death, has created a new basis for the pursuit of former Nazi war criminals, according to investigators.

After a protracted trial, the judge in the Demjanjuk case came to the conclusion that it was sufficient to prove the presence of an accused in a concentration camp to convict him of accessory to murder. Every SS member and guard in a concentration camp was part of the “machinery of murder”, and such camps had been established and existed for no other purpose.

After the conviction of Demjanjuk in 2011, investigators at the Central Office for the Investigation of Nazi War Crimes in Ludwigsburg undertook a new review of files in order to track down more former guards in the concentration camps. According to initial reports, there could be up to 50 such people still alive.

The fact that many who were active in the crimes of the Nazis continue to live in Germany undisturbed seven decades after the liberation of the concentration camps underscores once again how the political and legal authorities systematically prevented the persecution of those collaborating in Nazi atrocities.

Relatively few of the thousands of Nazi war crimes have been dealt with in the courts. Since the end of the war, German authorities have investigated more than 100,000 cases, but only 6,500 guilty individuals have been convicted. And those convicted have received comparatively lenient sentences for the monstrous actions they committed. Those accused usually justified their activities by arguing they were “acting under orders in exceptional circumstances”—a line of argument that the courts were prepared to accept.

In this context, it is a scandal that other SS crimes, like the massacre in Sant’ Anna di Stazzema on August 12, 1944, which claimed the lives of 560 Italian women, men and children, remain unpunished.

The state prosecutor in Stuttgart announced on October 1, 2012, that it would not be initiating charges against any of those who participated in the massacre who are still alive, and that the decade-long investigation would cease. The reason given was that it had been impossible to prove that those accused had committed acts that had not yet “passed the statute of limitations”.

In the meantime, the association for the victims of Sant’ Anna have lodged an appeal with the state prosecutor. The appeal included a report by the Cologne-based historian Carlo Gentile, who is one of the most renowned academics with knowledge of the material surrounding the massacre. This was reported in the Süddeutsche Zeitung on April 15.

The state prosecutor had failed “absolutely” to consider important documents and statements from witnesses, wrote Gentile, and had made “clear mistakes regarding the historical data”. In their assessment of the massacre, they had “paid too little attention to the topography of the location and the time period involved”.

Above all, the massacre at Sant’ Anna could not be viewed as an “isolated episode”. The SS had left a bloody trail through Italy in 1944. Considering the number of massacres of civilians, all the available evidence pointed to a planned and well-organised war crime.