As mentioned by Michael Harvey, badge refers to an official police badge (provided he is a police officer).
Police officers are in an occupation that grants them certain privileges that normal citizens do not have; for example, they can perform traffic stops (pulling cars over), break traffic laws in order to quickly reach an emergency (running red lights, speeding), and do other things that enforcing the law requires.
A police officer is required to carry a badge to identify themselves, or they cannot exercise their authority as the general public cannot determine if they are indeed a police officer.
The assault or murder of a police officer is extremely serious compared to the assault or murder of a fellow citizen. That is why he makes the distinction badge or no badge, meaning whether you are a policeman or not.