A cadeia de custódia e a prova penal digital

Abstract

The present research approaches the institute of the chain of custody of the digital criminal evidence as a necessary instrument to demonstrate the reliability of the evidence and the effectiveness of the guarantee to the adversary. The objective of this paper is to elucidate whether the requirement of adopting the evidence of chain of custody, provided for in the Criminal Procedure Code, is extensive to digital evidence, as well as to identify which procedures could be used in order to guarantee the authenticity of the digital criminal evidence. Therefore, through the deductive approach method and documental and bibliographic research the project aimed to outline the general aspects of criminal evidence, its principles and limitations. Subsequently, the technological means of investigating evidence and digital evidence were analysed, observing the need to preserve the chain of custody in view of the fragility of these elements. Furthermore, the provisions of the chain of custody of material evidence provided in the Criminal Procedure Code and the incompatibility with digital evidence were examined. Afterwards, good practice procedures were presented for the identification, collection, acquisition and preservation of digital evidence, proposing their observance in the custody chain of digital evidence, emphasizing the techniques of mirroring and immediate preservation using cryptography. Finally, the consequences of irregularities in the chain of custody of the digital evidence were analysed for the criminal proceedings, verifying that, for now, in the absence of mandatory by force of law regarding the procedures of good practices, such failures should be examined in the valuation phase. In the end, it is concluded that by allowing full access and offering a certain guarantee to the preservation of the authenticity and integrity of the evidence, in order to enable the exercise of the adversary system, the requirement of adopting the chain of custody of the evidence extends to digital evidence, being necessary to respect the observance of procedures provided for in technical standards in the custody of this evidence.