The procedural institution of pretrial detention is becoming increasingly important, its practical incidence has increased enormously, and its automated application is often harshly criticized. For this reason, in the present study we sought to analyze the practical application of the principle of proportionality in the orders that declare the requirement of preventive detention founded, issued in the Judicial District of La Libertad, in the year 2021. In order to achieve this purpose, a detailed study of seven preventive detention orders was carried out in which the request for the filing of this precautionary measure has been declared founded, with this, it was possible to examine the way in which its work has been carried out. application in the Judicial District of La Libertad. In addition to this, some surveys were applied to various legal operators with the aim of being able to gat...