Purpose: Psychological expertise is a technical and methodological procedure, recognized for its relevance and usefulness. Theoretical Framework: The theoretical basis that we propose is based on Undeutsch’s hypothesis, which states that the events that happen differ in content, quality and expression from those that are imaginary. In the justice system, they determine the psychological affectation, of events occurred within. Method: The privacy and to provide methodological rigor, must be subjected to the credibility of the testimony, in this sense, the aim is to determine the importance of the credibility of the testimony in the psychological expertise, in victims of violence, for which it has been taken into consideration, documents in English and Spanish of the search engines Scopus. Result: Redalyc, Researchgate, Semantic Scholar, finding 361 documents of which 7 experimental research studies were selected, whose research instrument was the semi-structured cognitive interview, subjected to criteria-based content analysis (CBCA), and external verification, highlighting that these documents agree that the credibility of testimony is fundamental to sustain psychological expertise in a judicial process. Conclusion: For the present work, we have focused on experimental research, whose conclusions allow us to reaffirm that the interviews that give rise to psychological reports, in cases of violence that occurred in the private sphere, can be subjected to the credibility of testimony based on criteria and external corroboration, as they are unique evidence before the justice system.