Max de Crinis
Max de Crinis (1889-1945) was a German academic psychiatrist who worked with the Nazis in a number of efforts, including the planning of the euthanasia program and, assisting counterespionage personnel of the SD, in field operations. He assisted Walter Schellenberg in capturing British agents in the Venlo Incident.
De Crinis, who Robert Jay Lifton called the "most outspoken and influential Nazi in the German psychiatric establishment", was both a respected physician and a Nazi activist. He worked with the RuSHA, but also performed respected research and probably protected some concentration camp and potential euthanasia victims. After he examined Hitler and diagnosed Parkinson's disease, he was part of an initiative for a 1945 armistice with the West, working with Heinrich Himmler, Leonardo Conti, and Walter Schellenberg. 
He committed suicide in May 1945.
- Robert Jay Lifton (1986), The Nazi Doctors: medical killing and the psychology of genocide, Basic Books, p. 65
- Gerstenbrand, Franz and Karamat, Elisabeth (1999), "(Abstract) Adolf Hitler's Parkinson's disease and an attempt to analyse his personality structure", European Journal of Neurology 6
- Lifton, pp. 120-122