The means of obtaining evidence used in the preliminary phase of criminal prosecution, especially in cases of organized crime, have become more sophisticated. For some time, legislation has provided for exceptional means of obtaining evidence or hidden methods of investigation, loaded, as the name implies, with secrecy. The characteristics of this type of criminality, which is continuous or permanent and has no direct victim, among other specificities, represent challenges to the traditional model of preliminary investigation, which was compelled to make use of new instruments of criminal prosecution, such as telephone interception, telematics , environmental capture of electromagnetic, optical or acoustic signals, and methods such as controlled action and infiltration of agents, among others. In this sense, the possibilities of using technology, through the search for traces, data and information, stored or in transit, significantly change the traditional forms of criminal investigation. Furthermore, surveillance technologies, especially in digital media, have blurred the boundary between the prevention and repression of crimes, between public security and criminal prosecution. On the other hand, the protection of secrecy of communications and privacy, the issues of the use of personal data in the scope of public security and in criminal investigations, tension such uses. These issues require reflection and efforts in order to discuss pressing problems, stress possibilities, draw limits, verify the sufficiency of normative regulation, the exceptionality or expansion of the use of these technologies in criminal investigation.