Mitläufer
Mitlaufer is a German term (plural: Mitlaufer) used in the denazification proceedings in West Germany after World War II to describe people who supported Nazism without directly participating in Nazi atrocities such as genocide. Mitlaufer is usually translated in English as either "fellow-traveler" or "hanger-on".
Other websites
http://www.woxikon.com/wort/mitl%C3%A4ufer.php
Nuremberg trials