The changes of investigation thinking, path, way and content react on the principle of investigation. Principle refers to the universal meaning.

Through the study of criminology principles, investigators can better understand the thinking mode and behavior habits of criminals, thus guiding the investigation work.

What should the public security major learn?

Public security major is a comprehensive subject, involving many aspects of knowledge and skills. The following are common learning contents for public security majors:

1, legal basis: learn criminal law, public security management law, criminal procedure law and other legal knowledge, understand the basic principles and applicable provisions of the law, and master the writing skills of legal documents.

2. Criminology: study the causes, characteristics, types, prevention and control of crime, and learn criminal psychology, criminology theory, criminal investigation and other related knowledge.

3. Public security science: study the causes, characteristics and governance measures of social security problems, learn the theory and methods of public security management, and master the basic means and skills to maintain social stability.

4. Criminal science and technology: learn the basic principles and application methods of criminal science and technology such as on-site investigation, trace identification, fingerprint technology and DNA technology, and have the practical ability of criminal science and technology.

5. Public security management: learn the organizational structure, functions and management mode of public security organs, and master management knowledge and skills such as administration, leadership and public relations.

6. Investigation: learn the basic principles and methods of criminal investigation, learn investigation techniques such as information collection, surveillance and evidence collection, interrogation and interrogation, and cultivate the ability of case investigation.

7. Safety precautions: learn the principles and measures of safety precautions, including safety, preventive technology and emergency management.

8. Psychology: Learn the basic knowledge of psychology, understand people's behavior and psychological characteristics, and have certain psychological consultation and negotiation skills.