STUTTGART, Germany — After years of relative inaction, German prosecutors have opened dozens of fresh investigations of men and women suspected of having served as Nazi death camp guards, racing against the clock to bring the aging suspects to justice. Not since the end of World War II have so many cases been initiated at once.

The surge of cases is being driven by a new generation of prosecutors — the “grandchildren generation,” as they are known here — who bring a less conflicted view of culpability to crimes committed during the war and who were given a legal opening with the 2011 conviction of John Demjanjuk, a former guard at the Sobibor death camp who spent years as an Ohio autoworker.

The prosecutors are now applying modern advances to historical crimes, like three-dimensional virtual models of camps to demonstrate what guards would have been able to see from their posts, as well as spreadsheets and databases to glean critical evidence from reams of Nazi archival material.

Since March alone, prosecutors from Stuttgart to Schwerin and Hamburg to Frankfurt have opened inquiries against men and women suspected of playing a role in the functioning of the Auschwitz-Birkenau camp, cases that could eventually lead to charges of complicity in the murder of tens of thousands of the more than one million Jews and others who perished there.