When you commit a crime, you will eventually be cracked by the intelligence or investigative authority. In this occasion, they have frequently employed a methodology of the good cop and bad cop.
Intelligence operation is fundamentally conducted by the multiple operatives. When they need to talk to their subject directly, one of them plays a part of the good cop and another assumes a part of the bad. As far as the multiple agents are deployed, they should run a mission in this way, as it is more efficient.
This methodology is employed to crack a subject who commits an issue legally in a gray area, as it is effective enough to create a confession. Moreover, they oppress a target to make a false confession, which is used as a leverage to hire this subject as an asset.
The intelligence objective is an assetization, hence this system is not necessarily used against a criminal activity. They shake their target mentally in this system, which is one of the steps to hire this individual as an asset in general.
The bad cop plays a role to intimidate a subject at least mentally to fall into their hands. Some of the subjects are cracked just by an oppression, therefore, the bad continues to hit them.
There are others who cannot fall just by intimidation, which is a time when the good cop shows up. This goody condemns the baddy’s unethical and illegal conducts and buys a trust of them. This reliance can be leverage to hire them as an intelligence asset.
Even if this system does not work in one cycle, the spy recurs this turnaround until the target falls into either of them. In this methodology, the subject is hugely shaken to take an either of chance.
This good cop and bad cop is just a system, nothing to do with their true nature. It might work better to assign these roles along with their personalities, but it is more important to run these roles systematically.
This methodology can be used when the spy does not capture a target in their custody. They just intrude into a personal relationship of the subject, playing a role of the goody and baddy, either of those eventually can control the target.