Huh? Mengele was playing at sadism, nothing more. Injecting dyes into twin's eyes to see if he could create Aryan eye colour, shooting and autopsying a still warm inmate to win a bet of whose diagnosis was correct, connecting up twins to try and make them conjoined.

His medical defence was specifically denied as he did nothing to contribute to the Nazi war effort.

He did none of the valid, but unethical, Nazi research like the well known hypothermia experiments.