Federal prosecutor Eli M. Rosenbaum, 54, is on the trail of mass murderers, but you won’t see a story like his on CSI. There is no crime scene to study, the witnesses are long dead, and the evidence is scattered worldwide. The director of the U.S. Department of Justice’s Office of Special Investigations (OSI), Rosenbaum is America’s chief Nazi hunter. Sixty-five years after the end of the Second World War, he is still tracking down its last surviving criminals.

With time finishing the job of the Nuremberg trials—the last judgment on Hitler’s henchmen—t he U.S. government plans to merge the OSI into a broader war-crimes effort. Yet Rosenbaum won’t rest until the last Nazi is brought to justice.

Photos: See 21 Nazis Captured in the United States

For him, peeling back the past and reviving horrific memories in Holocaust survivors has been a heartbreaking process. “I can always tell when the next question will lead them to start crying,” he says. Why does he find it so important to spend government resources going after elderly enemies who surely represent no further threat? “American families sacrificed 200,000 sons and daughters to end Nazi tyranny,” Rosenbaum says. He learned about the horrors of the concentration camps from his G.I. father, who reported on Dachau after its liberation. The young Eli once asked, “What did you see?” The elder Rosenbaum didn’t answer, but his eyes—a quarter-century after he entered the place where more than 30,000 prisoners were murdered—welled with tears.

Federal prosecutor Eli M. Rosenbaum

Hundreds of Nazi war criminals and collaborators are believed to have infiltrated the U.S. after 1945, and by some calculations, the Nazis sought by the OSI were linked to the murders of as many as 2 million (of the 6 million) Jews killed under Hitler’s orders. Most of the criminals have died, or as Rosenbaum puts it, “aged out.” He guesses that a few dozen at most may remain here alive.

For many years following the war, U.S. officials were lax in tracking down wanted Nazis. For example, even after a tip from Austrian Nazi hunter Simon Wiesenthal led The New York Times in 1964 to expose a local housewife, Hermine Braunsteiner Ryan, as a former guard at Poland’s Majdanek death camp, U.S. authorities showed little interest in further investigation. There was no coordinated approach until the 1970s, when the press and Rep. Elizabeth Holtzman (D., N.Y.) aired a slew of embarrassments. Notably, Croatian Nazi leader Andrija Artukovic, implicated in up to 700,000 killings, turned up in California. He was extradited to then-Yugoslavia and convicted of war crimes. (He died in 1988 while on death row.)

Finally, in 1977, the U.S. government set up a Nazi crimes unit. Rosenbaum, whose paternal grandparents lost relatives in the Holocaust, joined it after graduating from Harvard Law School in 1980. He left in the mid-’80s to work at a law firm and then at the World Jewish Congress, where he played a key role in exposing the Nazi past of former U.N. Secretary General Kurt Waldheim. He returned to the OSI in 1988 and became its head in 1994.

Since the U.S. has no criminal jurisdiction over World War II crimes committed abroad, it cannot prosecute those murders. However, the OSI has won denaturalization and deportation cases against 107 accused Nazis and lost only six. While most murder investigations begin with the crime and work backwards to find a suspect, OSI’s cases go in reverse. They result from the painstaking matching of Nazi records to immigration rosters by the unit’s lawyers, historians, and support staff.

“My specialty is questioning suspects,” Rosenbaum says. As a young investigator, he confronted Juozas Kisielaitis, a suspected member of a Lithuanian murder battalion, in his tailor shop in Worcester, Mass., in 1981. No, Kisielaitis insisted, he had no ties in that country. In response, Rosenbaum took out a wartime wedding portrait from Nazi-occupied Lithuania that showed the man had been married there and also mentioned the couple’s son, who still lived in that country. Faced with such damning evidence, Kisielaitis abandoned his denials and fled to Canada.

See More Nazis Who Were Captured in the United States

Also finding sanctuary up north was Helmut Oberlander, decorated for service in a death squad that executed 91,678 people in southern Russia. When Canadian authorities began prosecuting him, he vanished. Rosenbaum tracked him down in Florida and brought him to the airport to be returned to Canada. “It was May 8, 1995, the 50th anniversary of the day that victory was declared in Europe,” he remembers. The airport’s overhead TVs were showing the ceremonies. “It was surreal.”

One of Rosenbaum’s strangest cases was that of Elfriede Rinkel, who had been a guard at the Ravensbrück camp in northern Germany. A San Francisco resident, Rinkel had been married for 42 years to a German Jew who died shortly before her unmasking. After she was deported to Germany in 2006, she admitted she’d never told her spouse about her past.

In 2007, the OSI triumphed in a case that Rosenbaum calls the oldest killing proved in any U.S. court. John Kalymon, 88, a former Ukrainian auxiliary policeman and suspected Nazi collaborator who lived in Michigan, ended up being nailed by his own record-keeping. Investigators found Nazi documents from Ukraine in which Kalymon reported he “fired four shots while on duty,” killing one Jew and wounding another. The reports also said his unit delivered 2128 Jews to an assembly point in Lvov where 12 were “killed while escaping” and that Kalymon used four rounds of ammunition. Kalymon was stripped of U.S. citizenship, and a deportation case is proceeding against him.

“It’s chilling when you read something like that, the matter-of-fact reporting of shooting and murder,” Rosenbaum says.

The OSI’s actions have raised some criticism. Retired Ohio autoworker John Demjanjuk, 90—now on trial in Munich, Germany, as an accessory to the murders of more than 29,000 Jews at a Polish concentration camp—was originally charged as another man called “Ivan the Terrible.” Conservative commentator Pat Buchanan has long derided the OSI as a group of “hairy-chested Nazi hunters” and questioned why the U.S. is devoting money to “running down” aged camp guards.

But the Simon Wiesenthal Center, a Jewish human-rights organization, has given the U.S. alone its highest grade of A every year in its report card on efforts to bring Nazis to justice. David Marwell, the director of New York City’s Museum of Jewish Heritage, says of Rosenbaum: “He’s stamped OSI with his passion and absolute expertise.” Yet some of the prosecutor’s most prized tributes have come from victims. A survivor of Lithuania’s Vilna Ghetto who was dying of cancer still managed to testify at the trial of war criminals Algimantas Dailide and Kazys Gimzauskas. “He gave me an unforgettable hug afterwards,” Rosenbaum recalls.

The OSI’s nine pending cases could very well be the end of Nazi-hunting in America. The list includes Vladas Zajanckauskas, 94, of Sutton, Mass., a Lithuanian linked to the liquidation of Poland’s Warsaw Ghetto in 1943, when some 7000 people died; and Osyp Firishchak, 90, from the Chicago area, a former Ukrainian auxiliary policeman who allegedly served in Lvov.

Later this year, the OSI will be merged with another human-rights enforcement unit targeting modern-day war crimes. Rwandan-American Lazare Kobagaya, 83, accused of covering up his role in the 1994 Hutu-led genocide of Tutsis, is set for trial in Wichita in October. The Nazi cases have paved the way for these new ones, Rosenbaum says, and he has no plans to leave. “We’ve vindicated the rule of law. We’ve sent a loud, clear message that the U.S. is not willing to be the sanctuary for perpetrators of crimes against humanity.

“Part of me,” Rosenbaum continues, “believes we obtained more justice in our last years because pursuing these cases at such a late date sends a powerful message: If you’re guilty, you can reasonably expect to be pursued for the rest of your life.”

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