Análisis de contenido de las declaraciones de testigos: Evaluación de la validez científica y judicial de la hipótesis y la prueba forense

Assessing the credibility of a testimony is a crucial step in judicial decision-making, primarily when inconsistencies arise due to conflicting versions of events. The evaluation of the veracity of a testimony based on verbal cues, in particular those based on the Undeutsch hypothesis that contends that the memory of self-experienced real-life events differ in content and quality (as defined by reality criteria) from the memory of fabricated or fictitious accounts, is considered to be the most effective tool for assessing credibility. This hypothesis has given rise to a forensic technique known as Statement Validity Analysis (SRA) that includes a list of reality criteria i.e., Criteria Based Content Analysis (CBCA). Meta-analytical reviews support the discriminatory power of CBCA reality criteria and the CBCA total score in distinguishing between the memory of self-experienced real-life events versus fabricated or fictitious accounts in all types of populations (children and adults), witnesses (plaintiffs, witnesses, and defendants), and memories (sexual abuse, gender violence). A hypothesis must fulfil the Daubert standards for it to be admitted as scientific evidence in a court of law, as is the case of the Undeutsch hypothesis. Notwithstanding, the scientific evidence upholding this hypothesis in terms of reality criteria does not substantiate the validity of this forensic technique. A review of this technique revealed it failed to meet scientific criteria (CBCA is not a methodic system, and is neither valid nor reliable; and it lacks criterion validity as there is no strict objective decision criterion); and has legal and jurisprudential flaws (no safeguards guaranteeing the constitutional principle of the presumption of innocence; witness interviews to obtain statements may lack judicial validity; and fail to evaluate appropriately the consistency of the evidence). Finally, a forensic technique based on the content analysis of statements, the Global Evaluation System (GES), is examined in order to overcome the limitations of SVA.ResumenLa volaración de la credibilidad del testimonio es el ele­mento central en la gran mayoría de las decisiones judi­ciales, especialmente cuando se enfrentan versiones con­tradictorias de los hechos. La evaluación del testimonio basada en indicios cognitivos (verbales), específicamente la basada en la hipótesis Undeutsch que sostiene que la memoria de un evento auto-experimentado difiere en contenido y calidad (definida por criterios de realidad) de la memoria de un evento no experimentado, se ha mos­trado como la más efectiva en la valoración de la credibi­lidad. De esta hipótesis se derivó una técnica forense, el Statement Reality Analysis (SRA), que incluye un listado de criterios de realidad, el Criteria Based Content Analysis (CBCA). Revisiones meta-analíticas prestan apoyo a la capacidad discriminativa entre memorias de eventos auto-experimentados y no experimentados de las categorías de realidad del CBCA, así como de la puntua­ción total del CBCA, en todo tipo de poblaciones (meno­res y adultos) y testigos (denunciantes, testigos y denun­ciados), y de memorias (abusos sexuales, violencia de género). Una hipótesis para ser admitida como científica en la Sala de Justicia ha de cumplir los criterios Daubert que, constatamos, cumple la hipótesis Undeutsch. No obstante, este soporte de la evidencia científica a la hipó­tesis a través de los criterios de realidad no significa que la técnica forense sea válida. Revisada la técnica verifi­camos que no cumple los criterios científicos (el CBCA no es un sistema metódico, esto es, fiable y válido; y adolece de validez criterial al no incluir criterio de deci­sión objetivo y estricto) y legales y jurisprudenciales (no garantiza el cumplimiento del principio constitucional de presunción de inocencia; la entrevista de obtención de la declaración puede dar lugar a una prueba carente de vali­dez jurídica; no evalúa adecuadamente la persistencia en la incriminación). Finalmente, se describe una técnica forense, el Sistema de Evaluación Global (SEG), basada en análisis de contenido de las declaraciones que solventa estas limitaciones del SVA. AbstractAssessing the credibility of a testimony is a crucial step in judicial decision-making, primarily when inconsistencies arise due to conflicting versions of events. The evaluation of the veracity of a testimony based on verbal cues, in particular those based on the Undeutsch hypothesis that contends that the memory of self-experienced real-life events differ in content and quality (as defined by reality criteria) from the memory of fabricated or fictitious accounts, is considered to be the most effective tool for assessing credibility. This hypothesis has given rise to a forensic technique known as Statement Validity Analysis (SRA) that includes a list of reality criteria i.e., Criteria Based Content Analysis (CBCA). Meta-analytical reviews support the discriminatory power of CBCA reality criteria and the CBCA total score in distinguishing between the memory of self-experienced real-life events versus fabricated or fictitious accounts in all types of populations (children and adults), witnesses (plaintiffs, witnesses, and defendants), and memories (sexual abuse, gender violence). A hypothesis must fulfil the Daubert standards for it to be admitted as scientific evidence in a court of law, as is the case of the Undeutsch hypothesis. Notwithstanding, the scientific evidence upholding this hypothesis in terms of reality criteria does not substantiate the validity of this forensic technique. A review of this technique revealed it failed to meet scientific criteria (CBCA is not a methodic system, and is neither valid nor reliable; and it lacks criterion validity as there is no strict objective decision criterion); and has legal and jurisprudential flaws (no safeguards guaranteeing the constitutional principle of the presumption of innocence; witness interviews to obtain statements may lack judicial validity; and fail to evaluate appropriately the consistency of the evidence). Finally, a forensic technique based on the content analysis of statements, the Global Evaluation System (GES), is examined in order to overcome the limitations of SVA.