Hur potentiellt AI-genererad bevisning påverkar beviskravet – En studie om robusthet och sannolikhet

Sammanfattning

This thesis examines how the rapid advancement of artificial intelligence, with a specific focus on generated imagery, impacts evidence and the duty to inve-stigate within Swedish criminal procedure. Grounded in the principles of free admissibility of evidence and the free evaluation of evidence under Chapter 35, Section 1 of the Swedish Code of Judicial Procedure, the study analyzes how courts evaluate, or ought to evaluate, defense claims that digital evidence has been manipulated. The study combines a legal dogmatic method with two interdisciplinary frameworks: Probabilistic evidence theory (the Bayesian method) and law and economics (cost-benefit analysis) Through the concept of robustness, the the-sis investigates whether an investigation can be deemed sufficient to support a conviction when facing a general or specific risk of digital manipulation. An investigation lacks robustness if additional, hypothetical investigation measu-res could reasonably alter the strength of the existing evidence in favor of the defendant. The thesis applies these theoretical models to contemporary Swedish lower court case law. The analyzis demonstrates that an objection regarding AI ma-nipulation does not diminish the aggregate probative value if the remaining investigation is sufficiently robust. In such scenarios, the objection can be dismissed as an ex post fabrication. Conversely, if the digital evidence i central to the prosecution’s case and the remaining investigation lacks independent corroboration, forensic authentication becomes essential to satisfy the standard of proof. Lastly, the thesis establishes an economic benchmark for the prosecutor’s duty to investigate during the preliminary inquiry. Given that state resources are finite and a routine authentication of all digital evidence would overwhelm the National Forensic Centre, forensic verifications must be constrained by cost-benefit parameters. An investigation is justified only when the potential of the verification to alter the outcome of the case (switch-ability) is real, which is determined by balancing the centrality of the evidence against how its digital and physical handling has been documented.