Earlier quoted context omitted.
Nope, it is not their job. If a citizen is accused in a crime, there are other institutions tasked with the investigation. Sometimes this is the counterintelligence, sometimes this is the police. However, breaking the law and actively avoiding legal supervision is a crime which makes them criminals.
Ok so we have to play by the rules to the absolute T. But our adversaries like China/Russia can play dirty and anyway they want, because you say justice is absolute and black and white. Great.
This seems like a fairly extraordinary claim that you haven’t backed with either evidence or logic.