It can be said that this work is concerned with showing the institute of police investigation in a clear and transparent way. This article seeks to study the importance of the investigation from its beginning to its conclusion. A bibliographic research was carried out carefully examining authors such as Alexandre Cebrian Araújo Reis, Victor Eduardo Rios Gonçalves, Fernando Capez, among others, aiming to highlight the main points that make the procedure of the police investigation so exciting. It ends by highlighting that this work is also intended to show the importance of the investigation in typically police activities, safeguarding the interests of the investigated individual and the interests of the community.