As  part  of  the implementation of the adversarial system in Costa Rica’s criminal procedure and the imminent elimination of the Forensic Medical Council, it becomes necessary that forensic psychiatrists and psychologists know what the new challenges are, because they will face to them in trial and questioned in relationship to the skilled procedures that they practice on minors that are victim of sexual aggressions. It is very important to know the accreditation system of an expert witness and what are the most frequent critics that are made by the law operators to their skilled procedures. The old belief is broken that Judges, prosecutors and defenders of the criminal process trust -in an unquestionable way- the skilled psychiatric and psychological procedures that are practiced to the young victims; this information has been obtained by a survey that was practiced to the mentioned public employees.  It is also mentioned, are the methodologies to that should be used on victims of sexual aggression, and those that should be eliminated from forensic practices, as well as the guidelines that are suggested, when approaching young victims.

Sexual Aggression; Psychiatry; Psychological skilled procedures; Adversarial System; Offended minor; Credibility; System of Accreditation of Expert witness