There are two case-handling modes. One mode is called the normal mode. When a major case occurs, the criminal investigation detachment, brigade, police station, and patrol police are all mobilized. In this mode, there will be no situation where the criminal police are overwhelmed because they have an overwhelming advantage in terms of force and numbers.
The second model, commonly used in some countries, is the departmental investigation model. Taxation, white-collar crime, anti-smuggling, anti-drug, and drug control all have specialized agencies and departments to investigate related cases. Investigators are called agents or investigators, but they don't represent everything; there are also supporting institutions such as crime labs, technical departments, and forensic experts. This model
