Professor Maximinus Friedrich Alexander de Crinis (29 May 1889 in Ehrenhausen near Graz – 2 May 1945 in Stahnsdorf near Berlin) held a Chair in psychiatry in Cologne and Berlin, and was a medical expert for the Action T4 Euthanasia Program who wrote the Euthanasia Decree, signed by Adolf Hitler on September 20, 1939.
An Austrian, he joined the Nazi Party in 1931. Not only an SS member, he was the most outspoken and influential Nazi in German psychiatry, a psychiatric consultant at the highest level of the regime. De Crinis became medical director of the Ministry of Education in 1941. He was also a director of the European League for Mental Hygiene.
On May 1, 1945, after killing his family with potassium cyanide, de Crinis committed suicide by taking a cyanide tablet.