NEW YORK — After decades of a mostly peaceful existence, delivering potato chips in New York City and then living in the quiet upstate New York countryside, Jakob Reimer is about to revisit his Nazi past.

Reimer, 79, admits that he was a member of a Nazi SS unit, the murderous Trawniki death squad, which emptied Polish ghettoes of Jews and sent them to their deaths.

Prosecutors from the U.S. Justice Department's Office of Special Investigations and from the U.S. Attorney's Office are about to put Reimer on trial in an effort to get his U.S. citizenship revoked.

The trial is slated to begin Monday in the first denaturalization proceeding of a Nazi war criminal to take place in Manhattan, home to thousands of aging Holocaust survivors.

Reimer's defense attorney is Ramsey Clark, a former U.S. attorney general.

From 1941 to 1945, prosecutors say, Reimer played a pivotal role in the murder of thousands of Jews in the ghettos, and sent millions more to their fate in labor and death camps.

If the prosecutors succeed in proving that Reimer lied on his 1952 application for a U.S. visa, they will be able to strip him of his citizenship and initiate deportation proceedings against him.

The OSI, the section of the Justice Department charged with prosecuting Nazi war criminals, interviewed Reimer in 1992.

He told Neal Sher, then OSI's director, and Eli Rosenbaum, then No. 2 in the department, that he was not a ghetto liquidator but served as a stockroom guardsman.

He admitted, however, that he had shot a Jew to death in a massacre at a ravine just outside of Trawniki.

When he arrived at a ravine outside Trawniki in eastern Poland, Reimer said, his colleagues had shot 50 or 60 Jewish men.

He said that although he was a supervisor, he was late because he had overslept.

When he arrived and looked into the pit, one man was still alive and pointing to his head.

According to the OSI transcript, Rosenbaum said, "You finished him off."

"I'm afraid so," Reimer responded.