ABSTRACT In the present work, the assessment of the rooting in the preventive prisons processed before the courts of preparatory investigation of Tarapoto, during the year 2016 was investigated. Having as a general objective to determine how the appraisal of the arraigo is carried out in the preventive prisons processed before these courts, an observational guide was applied as well as a documentary analysis guide, using the inductive, deductive and analysis - synthesis methods, in turn exegetical and hermeneutics, and as a technique, documentary observation and documentary analysis were used. The main result was that most of the preventive custody proceedings are related to the crime of Illicit Drug Trafficking - TID, twenty three (23) of the forty (40) Preventive Prison Hearing Registry Acts collected on this matter , likewise the fiscal headquarters required preventive detention for a...