CONTROLLED CONTAMINATION OF DIGITAL EVIDENCE: CONCEPTUAL PROPOSAL AND EXPERIMENTAL VALIDATION IN AN ACQUISITION SCENARIO

This study investigates the feasibility and applicability of the concept of Controlled Contamination in computer forensics, analyzing whether documenting and isolating contamination in specific scenarios enables the use of digital traces without compromising their validity. Based on international guidelines and current national legislation, the study addresses concepts related to the preservation of evidence, the chain of custody, and evidentiary integrity. The methodology combines a literature review with practical experimentation to analyze studies on the contamination of digital traces and their effects on the reliability of the evidence. The experimental study was conducted in a controlled environment that simulated a scenario in which data were transferred from a cloud to a hard drive, which was subsequently imaged, enabling detailed forensic analysis of the traceability of the contamination. The results provide evidence on the possibility of maintaining the validity of the evidence in specific scenarios, provided that contamination is appropriately documented and traced, thereby enabling a comparative analysis with existing studies on the chain of custody and evidentiary admissibility. This research proposes an innovative approach that could redefine how digital evidence contamination is handled, directly impacting forensic practices, expert training, and how courts evaluate digital evidence. Furthermore, the research may inform the development of new guidelines, within legal limits, that permit the analysis and use of certain types of partially contaminated evidence in criminal investigations and legal proceedings. The originality of this study lies in the introduction of the concept of Controlled Contamination and the practical demonstration of its viability in specific scenarios, highlighting the importance of rigorous documentation to maintain the reliability of digital evidence. The study seeks to expand chain-of-custody guidelines and to advance methodological approaches in computer forensics, thereby improving understanding of the effects of contamination and enabling the development of new criteria for evaluating the admissibility of digital evidence in legal contexts.