Michael Karkoc works in his yard in Minneapolis in May 2014. Poland will seek the arrest and extradition of Karkoc, who the Associated Press says is a former commander in an SS-led unit that burned Polish villages and killed civilians in World War II, prosecutors said Monday. (Richard Sennott/Star Tribune via AP)

It's unclear whether the Nazi unit commander knew precisely who had killed an officer in an attack near a Polish village — but there was no doubt about who was going to be punished.

In the summer of 1944, the commander turned his attention to civilians in two Polish villages and ordered his troops: “Liquidate all the residents.”

The next morning, according to the Guardian, soldiers started setting villagers' homes on fire, then shooting anyone who tried to get away.

“You could hear machine-gun shots and grenade explosions,” recalled Stanislawa Lipska, a survivor from one of the villages, Chlaniow. “Shots could be heard inside the village and on the outskirts. They were making sure no one escaped.”

Vasyl Malazhenski, a soldier in the company, recounted that he “could see the dead bodies of the killed residents: men, women, children.”

For decades, the commander who ordered the atrocity remained unknown, his war crimes unpunished even as Nazis and their collaborators have been pursued around the world.

Now, Polish authorities say, they know the identity of the man who issued the kill order for the Polish villagers.

After the Germans surrendered and the war ended, the commander allegedly slipped into the United States, lied about his military service and settled into a squat, one-story brick house in Minneapolis, according to the Associated Press.

Poland announced  Monday that it will seek the arrest and extradition of Michael Karkoc, a 98-year-old U.S. citizen who suffers from Alzheimer's disease.

Prosecutors are seeking his extradition despite his disease. If convicted in the killing of citizens in Chlaniow and Wladyslawin, he could spend the rest of his life in prison.

Karkoc's family has denied the allegations and offered a record of the older man's past that contradicts the AP's account. Karkoc's son, Andriy, called the accusations “evil, fabricated, intolerable and malicious.”

“I would like to get these people in a court of law to inflict the pain we have gone through,” he said.

But prosecutors had strong evidence of their own.

According to the Minneapolis Star Tribune, one report “uncovered evidence that Karkoc ordered his men in 1944 to attack a Polish village in which dozens of civilians were killed, contradicting statements from his family that he was never at the scene. The stories were based on wartime documents, testimony from other members of the unit and Karkoc’s own Ukrainian-language memoir.”

Prosecutors in Germany previously launched their own investigation of Karkoc after stories in 2013 by the AP revealed that he had been a commander in the SS-led unit that had committed war crimes in Poland. Kresy.pl, a Polish-language web portal, was also trying to identify the man responsible for the massacre. The organization and a British researcher used facial recognition technology that ultimately helped them determine Karcoc's identity.

The Germans never expressed doubts about Karkoc’s identity, but shelved their investigation after saying they had received “comprehensive medical documentation” from doctors at the geriatric hospital in the United States where he was being treated that led them to conclude that he was not fit for trial.

And then there were his own Ukranian-language memoirs, which were published in 1995, according to the Guardian.

In it, he said he joined the German army after the Nazi invasion of the Soviet Union in 1941, and earned an Iron Cross for bravery. He asked the Nazis to form the Ukrainian Self Defence Legion, which ultimately numbered 600 before it was subsumed into the SS Galician Division in 1945. Karkoc served there until the war's end, the Guardian reported.

He even wrote about the attack near Chlaniow that resulted in the death of Siegfried Assmuss, the commander whose death sparked the village atrocity.

“We lost an irreplaceable commander, Assmuss,” Karcoc wrote.

The account makes no mention of the 44 deaths that followed.

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Anne Frank and her family were also denied entry as refugees to the U.S.