El rol del juez penal en la valoración de la prueba y cadena de custodia.

Abstract

This research focused on analyzing the nature of criminal evidence in Ecuador and its relationship with the chain of custody as a limit to judicial assessment. Within the framework of the Comprehensive Organic Criminal Code (COIP), it examines a boundary between the principle of free assessment of evidence and the need to guarantee the authenticity of evidentiary items, through a doctrinal, normative, and comparative law study contrasting Ecuadorian legislation with the models of the United States and Ireland. It demonstrates that the chain of custody is not an administrative formality, but a substantive procedural guarantee. The study concludes that serious breaks in the traceability of evidence directly affect its reliability, which prevents the judge from exercising sound judgment (sana crítica) over it. Consequently, it establishes that violations of the chain of custody (Arts. 604 and 605 of the COIP) must necessarily result in the exclusion of evidence to protect the legitimacy of the criminal process and the right to defense, moving beyond the notion that such deficiencies only affect the evidentiary weight and not its admissibility.