Didn't I just read somewhere that the USA offered many of the doctors and scientists who worked within the Nazi system, work in this country after the war was over? The trade off was immunity - no charges for their part (if any) in crimes against humanit that may have been committed if research and data is continued in the west. I must see if I can find this data - sammieswife.
Not just Nazi they also gave it to Japanese Biological Warfare scientist the ones that are responsible for out breaks of plague in China. Which still linger even today. Apparently they perfected a delivery system involving hibernating fleas. They also did things that would make Joe Mangela and Jeffry Dahmer pass out.