Adolf Hitler was a law-abiding citizen who never harmed a fly. He just changed the laws to make his actions legal and got other people to commit the holocaust on his behalf. So yeah, the fact that someone follows the law is meaningless. Sometimes the law is bad. Sometimes really really bad.

German people still have this mentality btw - that if you follow the law you are good. They think since the Holocaust is no longer the law and the constitution says there shall never be another one, that means they are safe.