Chain of Custody, Digital Evidence, and Hash Values: An Analysis of STJ Precedents considering the Accusatory Criminal Procedure

Abstract

This article aims to analyze the precedents of the Superior Court of Justice (STJ) regarding digital evidence, mapping how precedents are reasoned when the defense requests the nullity of evidence due to a lack of integrity in the chain of custody, given the absence of a hash code in digital files. The research is justified by the current relevance of the subject, especially considering that in the last year five times more decisions were handed down than in the previous ten years, in a comparison with the research conducted by previous empirical analysis. To this end, a literature review on criminal procedure and digital evidence was used, as well as an empirical methodology through the systematic analysis of STJ decisions whose headnotes (ementa) contained the word hash. The descriptive and critical mapping of the decisions had its results presented through a combination of quantitative and qualitative methods. Consequently, it is verified that most precedents suffer from a justification deficit, removing from the prosecuting State the burden of proof regarding the validity of the digital evidence and placing upon the defense the task of proving prejudice in the specific case, in violation of the accusatory system.