RESUMEN
Molecular genetic technologies used in forensic medical expert evaluations help quantitatively evaluate the significance of coincidence or non-coincidence of signs in personality identification and in expert evaluation of kinship identification (disputable paternity or maternity). The level of validity of evidences, which can be considered necessary and sufficient, is the principal problem in such cases. Analyzing a complex case with disputable maternity, the authors discuss problems illustrating the necessity of attaining a high level of validity of the results for drawing a justified expert conclusion. Only high validity standard can rule out errors in interpretation of the results, otherwise the significance of the detected complex of signs can be insufficient for an unambiguous solution of an expert task.