How do you know someone is a bigot?

The question I ask for this one is "Is there an egregious double standard?" Specifically, does the person hold the target group up to a higher standard than others so that that group is subject to frequent or constant condemnation that others are not. For example, say a white person is quick to denounce a violent crime when the perpetrator is black but slow to denounce the same crime when the perpetrator is white then there is a double standard. Even more, if that same person is quick to condemn a black person for even a minor offense and slow to condemn a white person for the same, then that person is a bigot. It is true that someone can just be concerned with crime, but the double standard reveals that crime is merely a mechanism to condemn and not the issue itself.

I also apply this same test to someone being anti-Muslim, anti-Israel, anti-Semitic, anti-American...