Justified by the Nazis as “mercy killing,” the “Euthanasia Program” of medically-authorized murder was officially ordered by Adolf Hitler in October 1939.  The program targeted Germans who did not meet the Aryan racial ideal, such as physically- or mentally-disabled people and children of racially-mixed marriages.  In this program, German doctors transported “patients” from jails, hospitals, and sanitariums to specially-constructed “euthanasia centers,” and killed them with carbon monoxide gas.  This program served as a model for the Nazi Final Solution, and many of the program's doctors were later sent to Poland to assist in the murder campaigns of the Holocaust.