Procedural Transformation of Digital Evidence in Human Trafficking Cases: A Doctrinal Analysis of Kazakhstan’s Evidentiary Framework

Abstract

Human trafficking increasingly generates operational, documentary, and digital information, yet the availability of such information does not necessarily determine whether it can function as evidence in criminal proceedings. This study aims to examine the evidentiary structure of human trafficking proceedings in Kazakhstan by identifying the circumstances that must be proved, analysing how operational-investigative information acquires evidentiary value, and assessing the legal treatment of digital evidence. The study employs a normative/doctrinal legal research design based on primary legal materials, including Kazakhstan’s Penal Code, Criminal Procedure Code, Law on Operational Investigations, Law on Countering Human Trafficking, Digital Code, and relevant Supreme Court normative interpretations. The materials were analysed through three sequential stages: normative identification of circumstances subject to proof, procedural analysis of the transformation of investigative information into evidence, and a lex lata–gap–risk–lex ferenda analysis of digital evidence. The findings show that, first, the structure of proof in trafficking cases is offence-specific and multi-layered. Second, operational-investigative information and evidence capable of judicial use are not legally equivalent; evidentiary value depends on lawful procedural transformation, verification, fixation, and evaluation. Third, Kazakhstan already recognises various forms of digital information, but the applicable rules remain fragmented with respect to authentication, attribution, integrity, preservation, the digital chain of custody, and cross-border electronic evidence. The study implies the need for more coherent procedural guidance and digital forensic safeguards without weakening existing admissibility standards. Its originality lies in developing the concept of procedural transformation and integrating substantive proof requirements, investigative information, and digital-forensic safeguards into a hybrid evidentiary model for human trafficking proceedings.