Richard Sonnenfeldt; was lead Nuremberg interpreter

The cause was complications of a stroke, his son Michael said.

Mr. Sonnenfeldt later became an electrical engineer and was part of an RCA team that developed color television.

A German-born Jew who fled his native country at age 15, Mr. Sonnenfeldt found himself face to face with almost two dozen Nazi oppressors only seven years later, in 1945.

Among them were Hermann Goering, Hitler’s second in command; the industrialist Albert Speer, who ran Germany’s war manufacturing; and Joachim von Ribbentrop, the Nazi foreign minister. All were tried and convicted as war criminals by the International Military Tribunal in Nuremberg.

Mr. Sonnenfeldt, at the time a US Army private who had helped liberate the Dachau concentration camp, was plucked out of an Army motor pool to be chief interpreter, recognized as a rare native German speaker who had a firm command of English. In that role, he participated in the pretrial interrogations of prisoners, commonly held in the bare rooms of the Palace of Justice.

His first interrogation was of Goering, who had been Hitler’s designated successor. During the encounter, Mr. Sonnenfeldt said, he felt “the Jewish refugee I once had been tugging at my sleeve,’’ he wrote in his autobiography, “Witness to Nuremberg’’ (2006, Arcade Publishing).

Despite his nervousness, he said, he sharply reprimanded Goering for interrupting. “When I speak, you don’t interrupt me,’’ he said to Goering, recalling his words in an interview with Charlie Rose on PBS in 2007. “You wait until I’m finished. And then when you have to say something, I will listen to you and decide whether it’s necessary to translate it.’’

At one point, remembering a childhood joke, he addressed him as “Herr Gering,’’ a play on the name that means “little nothing’’ in German.

“He began as an interpreter but he evolved into a fairly significant interrogator,’’ said John Q. Barrett, a professor at St. John’s University who has written about the Nuremberg trials and was a friend of Mr. Sonnenfeldt’s. “He was the person who could really thrust and parry with the prisoner in his native tongue.’’

One of Mr. Sonnenfeldt’s duties was to read the indictments to each prisoner.

“As we went through the awful recital of crimes over and over, for each of the 21 inmates, hour after hour, I envisioned anew the stacks of pitiful corpses and gagged once again on the smell of assembly-line extermination these men and their cohorts had unleashed,’’ he wrote in his autobiography. “Their clean hands reached out for the bundles of stapled documents that cataloged their past. Elsewhere they might have easily have been taken for a group of very ordinary men, picked at random from a crowd.’’

Richard Wolfgang Sonnenfeldt grew up in Gardelegen, in northeastern Germany. In 1938, his parents, Walter and Gertrud Sonnenfeldt, both physicians, sent him and his younger brother, Helmut, to a boarding school in England as part of an attempt to move the family out of Germany.

Two years later, in the midst of war, Mr. Sonnenfeldt was declared an enemy alien because of his nationality and deported to Australia. (His brother, only 14, was allowed to stay.)

After arriving in Australia, he pleaded his desire as a Jew to fight the Nazis and was released. He began a long return journey, in which he set foot on five continents and survived a torpedo attack. In 1941, arriving in the United States, he was reunited with his brother and parents, who had escaped to Sweden and settled in the Baltimore area.

After becoming an American citizen, Mr. Sonnenfeldt was drafted into the US Army and fought in the Battle of the Bulge.

Mr. Sonnenfeldt returned to the United States before the trials were completed, turning down requests that he stay on. Enrolling at Johns Hopkins University, he studied electrical engineering and, after graduating, joined Radio Corp. of America, as RCA was known then. As part of the color television development team, he worked on transmitting color television signals.

He also did early work in the development of computers.

In his 70s, Mr. Sonnenfeldt, an avid sailor, crossed the Atlantic three times in his sailboat.