Due process, especially the police procedure, is a constitutional principle that the government must respect all of the legal rights owed to a person according to the law and the constitution. When a governmental activity harms a person without following the exact course of the law, it constitutes a due process violation which offends against the rule of law. This article mainly and briefly focuses on the justification of procedure conducted by the police force. Only when the justifications were completely fulfilled, could the constitutional rights of the people be realized and guaranteed.