Gilbert, a fluent German speaker, served as a prison psychologist in Nuremberg, arriving on October 20, 1945,[1] where he had close contact with those on trial.
The text is the verbatim notes Gilbert took immediately after having conversations with the prisoners, information backed up by essays he asked them to write about themselves.
During the process of the trials Gilbert became, after Douglas Kelley,[5][page needed] the confidant of Hermann Göring, Joachim von Ribbentrop, Wilhelm Keitel, Hans Frank, Oswald Pohl, Otto Ohlendorf, Rudolf Höss, and Ernst Kaltenbrunner, among others.
Gilbert and Kelley administered the Rorschach inkblot test to the 22 defendants in the Nazi leadership group prior to the first set of trials.
[6] Gilbert also participated in the Nuremberg trials as the American Military Chief Psychologist and provided testimony attesting to the sanity of Rudolf Hess.
In 1947 he published Nuremberg Diary, consisting of observations taken during interviews, interrogations, "eavesdropping" and conversations with German prisoners.
The 1948 London edition contains a foreword by Sir David Maxwell Fyfe, Deputy Chief Prosecutor for the British Legation.