Not once but twice, in the period 1987-2012, the Ukrainian-American John Demjanjuk was tried and convicted of of­fenses committed as a World War II death camp guard. Following each trial, one in Israel, the other in Germany, he appealed. The first appeal was successful: The Israeli prosecutors had charged the wrong man. The second appeal was not heard: The 91-year-old Demjanjuk died before the court could be convened, though the German prosecutors were confident his appeal would fail.

It is quite a story. The appalling Demjanjuk fought in the first years of the war in the Red Army. Captured by the Nazis, he in due course chose to become a guard in the Sobibor death camp. In the aftermath of the war, he found his way to the United States, a beneficiary of the 1948 Displaced Persons Act. He settled in Cleveland, taking a job in the automobile industry. He never revealed his Nazi past, which remained for decades undetected by the authorities. And then, in 1975, he was denounced as a war criminal by an American of Ukrainian descent.

After years of procedural wrangling in the United States over denaturalization and then extradition, Demjanjuk was tried and convicted in an Israeli court in 1988 as “Ivan Grozny” or “Ivan the Terrible,” a Treblinka death camp guard notorious even among the other guards as brutal, sadistic and murderous. It was a bad instance of mistaken identity; the impulse to honor survivors’ testimony, riddled with “perplexing and dismaying mistakes,” pushed the court in a wrong direction. In 1993 Demjanjuk’s conviction was overturned. To survivors’ despair, this mendacious, brutal man returned triumphant to the United States. He was prosecuted for offenses he had not committed (he was not a Treblinka guard), and it looked as if he would escape punishment for the grievous offenses he had committed (as a Sobibor guard).

Years later, the truth of his past, in all its genuine horror, was established, and this man, with his “deep reserves of self-pity” and his “ethos of adaptation and survival,” was a defendant once again, this time in a Munich court in Germany. Aided by the testimony of professional historians, the court was able to reach the correct verdict, one that was both “remarkable and just,” Lawrence Douglas writes in “The Right Wrong Man.”

Douglas, a professor of law at Amherst College, asks and answers some important questions. To begin with, is there justice in trying old men for crimes committed decades earlier? He answers yes. Notwithstanding the frailties and infirmities of age, and the passage of time, we continue to be responsible for our actions. There can be no reward for a resourceful criminal, merely more efficient in evading justice than most other criminals. What is more, when the crimes have a historical resonance, as in the Demjanjuk case, we get not just a verdict, but a lesson too. Douglas thus defends the “didactic trial,” which he carefully (and correctly) distinguishes from the “political trial” and the “show trial.” Demjanjuk had his defenders, of course. Douglas quotes a Pat Buchanan article, in which the onetime presidential candidate cast the former death camp guard as the victim of the “same satanic brew of hate and revenge that drove another innocent Man up Calvary that first Good Friday 2,000 years ago.”

Next, what reckoning should a nation make with its own past, when that past is both appalling and historic? This is sometimes referred to as the problem of “transitional justice.” Douglas finds that Germany’s much admired record in confronting its own terrible history fell short of actually bringing individual Nazi perpetrators to trial. Confronting the collective past, by means of memorials, symposiums and films, was one thing; prosecuting individuals for Nazi-era crimes was quite another. Indeed, in the Federal Republic, “the obstacles to successfully prosecuting former Nazis,” Douglas writes, “were many and formidable.” We should not be surprised by this, he adds: The simple fact is that postwar Germany was full of former Nazis. The Munich trial changed that: German judicial honor was restored.

Last, were there larger benefits to mankind that flowed from the Demjanjuk case? Once more, Douglas answers yes. First, it yielded a modified theory of culpability, directly “connected to the exterminatory process.” This disposed once and for all of the defense “I was no more than a cog in the machine,” and of its corollary, “I was only obeying orders.” A machine cannot run without its small constituent parts. As a result of the Demjanjuk case, it is now enough to prove that a defendant worked in a death factory; it is no longer necessary to prove that he committed wanton murder. In the formula: Guilt follows function, not act. Second, it prompted further investigation into other low-level perpetrators. Third, it demonstrated the ability of mature legal systems to learn from past mistakes, and thus strengthened public confidence in the justice delivered by American, Israeli and German courts — and more generally, the courts of liberal democracies.

Douglas relates with authority and clarity the story of these complex legal processes, which stretched across several decades. They constituted, he writes, “the most convoluted, lengthy and bizarre criminal case to arise from the Holocaust.” Douglas does justice to both the story’s factual complexities and its moral and political conundrums. He puts the trials in the dual context of the greater postwar judicial reckoning with Nazism and the Cold War, and shows how the long-drawn-out case exposed tensions both within and among the relevant three legal systems. “The Right Wrong Man,” from its summary title to its thoughtful postscript, is an impressive work, as well as a timely one in its demonstration of the power of legal systems to learn from past missteps.

nytimes.com