1. Zhang Dejun acted in self-defence. According to Article 63 of China's Criminal Procedure Law, "Any citizen can immediately hand over a person to a public security organ, a people's procuratorate or a people's court for handling under any of the following circumstances: (1) He is in the process of committing a crime or is found immediately after committing a crime", so the defendant's behavior of chasing the deceased Hu and Hu by car in this case is legal and justified.

The robber broke the law first. During the chase, Zhang Dejun did not directly cause his injury, and Zhang Dejun did not bear any responsibility.

3. In a country ruled by law, criminal cases advocate public relief, not private relief, otherwise it will fall into a passive embarrassment. Courage should also be within the framework of the law, not beyond the provisions of the law.

Write from the above three angles.