Theoretical Grounds for Applying Doctrinal Exceptions to the Rules of Inadmissibility to a Forensic Expert’s Opinion

The article examines the admissibility of derivative evidence in criminal proceedings. The relevance of the topic is determined by legal and reputational risks for forensic examination arising from abuse of exceptions to the general rules of inadmissibility. The purpose is to analyze the transformation of inadmissible evidence into admissible evidence, particularly through forensic examination, to clarify the boundaries of Evidence Laundering in the Ukrainian legal context, and to propose its introduction into scholarly discourse as an independent category denoting deliberate use of evidentiary information whose original source is procedurally inadmissible. The study applies general philosophical methods (analysis, synthesis, induction, abstraction) and special legal methods (dogmatic, comparative law, systemic interpretation). It is established that in Ukraine only evidence obtained with a substantial violation of human rights and freedoms can “poison” derivative evidence. In other cases, autonomy arises: if the primary evidence is inadmissible but obtained without such violation, its derivatives may remain procedurally admissible. The doctrine of fruit of the poisonous tree is interpreted as a procedural analogue of material-law concepts of causation (conditio sine qua non, alternative and cumulative causation). This explains why not every violation contaminates derivative evidence, and why exceptions of U.S. law (inevitable discovery, independent source, attenuation, good faith exception) represent weakened or interrupted causal chains. Criticism of inevitable discovery highlights the danger of replacing factual causation with hypothetical causation, often relied upon by the prosecution. A transfer of results of unlawful searches to a bona fide procedural acquirer is described by Levine, Turner, Wright (2016) as Evidence Laundering. The article argues for broader use of this term to denote any transformation of defective evidence into another procedural object. Such modification affects admissibility, allowing evidence to remain in proceedings despite the poisoned origin. Admissibility is emphasized as not absolute but the result of evaluation at a specific moment by a defined subject. Forensic examination, situated between derivative and independent evidence, plays a key role in balancing verification, study, and evaluation.

admissibility of evidence; procedural causality; doctrine of fruit of the poisonous tree; forensic examination