In the course of collecting historical material about the first psychoanalytic in-patient clinic ("Sanatorium Schloss Tegel") in the years 1927-1931, the authors discovered an unpublished typescript by Ernst Simmel entitled "Neurotic criminality and lust murder". On the basis of clinic records, excerpts from letters, and personal information, the authors supplement Simmel's treatment report of a lust murderess with a historical, documentary text, which is followed by Simmel's paper.