After service as a medical orderly during World War I Heinze studied medicine and trained as a psychiatrist at Leipzig, where he worked from 1924 in child psychiatry.
Here he supervised the murder by injection, starvation and poisoning of thousands of children whose brains he then supplied to Nazi researchers.
[3][4] Heinze was released from prison on 14 March 1952 and declined offers of senior medical posts in the Volkspolizei and at the University of Jena in order to return to his family in West Germany.
He took up the directorship of the department of child and adolescent psychiatry in the hospital of Wunstorf in Lower Saxony, where he remained until his retirement, and where he died in 1983.
As a result of Müller's request the Russian military legal service reviewed Heinze's case and in 1998 declared him rehabilitated.