(JTA) — German prosecutors said they had insufficient evidence to prosecute a 95-year-old man who was deported from the United States on suspicion of involvement in Nazi war crimes.

The Public Prosecutor’s Office in Celle, in northern Germany, dropped all charges last month against Friedrich Karl Berger, who was deported in February, Der Spiegel reported.

A U.S. Immigration judge last year found that Berger had served at a subcamp of the Neuengamme concentration camp system near Hamburg, where Jews and others had been held in “atrocious” conditions, as the court said.

Berger had entered the United States from Canada in 1959 and lived for many years in Tennessee, receiving a pension throughout from Germany for his military service.

He was deported under a 1978 law, known as the Holtzman Amendment, that bars anyone who participated in Nazi-sponsored persecution from entering or living in the United States. An appeals board upheld the decision in November.

Berger admitted to “guarding prisoners in a concentration camp which was not used for the systematic killing of the prisoners,” the prosecutors said in their decision to close the case. This “is not sufficient as such to prove the crime.”

Germany has prosecuted several accused accomplices to Nazi war crimes since the 2011 conviction in Munich of former concentration camp guard John Demjanjuk. The Demjanjuk case set a precedent that being a guard at a death camp was sufficient to prove complicity in murder.