Children are particularly vulnerable subjects in criminal justice. They cannot report abuse because of their young age, lack of knowledge, and victimization. The administration of criminal cases, in which both the offender and the victim are minors, determines the necessity to adopt a special approach by the authorities, to respect the rights and guarantees regulated by the legislation to victims and minor suspects or accused. However, we should mention that the commission of the offense by the perpetrator, who has not reached the age of criminal responsibility does not automatically determine the refusal to start criminal prosecution, the authorities being obliged to take reasonable measures, for the multilateral examination of the case and the application to the offender the non-criminal measures. The violation of the obligation of efficient and effective investigation of sexual abuse of a minor by the offender, who has not reached the age of criminal responsibility was found by the European Court of Human Rights in the case of A. P. C. Republic of Moldova application no. 41086/12 on 19 June 2012 decision on 26 October 2021. Within this study, we analyze the conclusions made by the High Court, the positive obligations of the state in the investigation of sexual crimes against children, as well as the importance of this decision in the realization of the rights of victims and minor offenders in the legal system of the Republic of Moldova.