A 94-year-old man deported from the United States for lying about his Nazi past is unfit for trial on allegations that he was an accessory to thousands of murders as an SS guard at Auschwitz, a German court said Friday, according to The Associated Press (AP).

The Ellwangen state court said Hans Lipschis is suffering from “worsening dementia” and couldn’t be tried.

Lipschis was charged with 10,510 counts of accessory to murder on allegations he served as a guard at the death camp from 1941 to 1943.

Stuttgart prosecutors said they hadn’t yet decided whether to appeal the decision, according to AP.

The court released Lipschis from custody in December, saying it had “considerable doubt” over his fitness to face trial.

Lipschis was arrested in southern Germany last May, after prosecutors concluded there was “compelling evidence” that he had been complicit in murder.

He acknowledged he served with the Waffen SS at Auschwitz, but claimed he was only a cook.

Lipschis’ attorney, Achim Baechle, told AP that after his release, Lipschis suffered a fall on his return home. He was then operated on, and is now in a nursing home.

“I assume the prosecutors will appeal the court’s decision, but I think the decision is absolutely correct,” he told the news agency.

Lipschis was deported from the U.S. in the early 1980s for lying about his Nazi past when he arrived in Chicago in 1956. He has lived in Germany since.

Lipschis is one of 30 suspected former Auschwitz guards against whom a special German prosecutors’ office in September said it had collected enough evidence to warrant charges.

Efraim Zuroff, the head Nazi hunter at the Simon Wiesenthal Center in Jerusalem, said he hoped the Lipschis decision would be a “wakeup call” for other prosecutors to prioritize the new Auschwitz cases.