The purpose of this book is to alert the legal community about the impact produced by new technologies on the means of evidence used in the different jurisdictional processes, especially those followed for homicide crimes committed with firearms, as a result of the manufacture and incorporation of the so-called "ecological or biodegradable ammunition" in the market of weapons for individual use, and the weaknesses of the Firearms Trace Detection (FTA) as a means of evidence against this type of technology in a significant number of Latin American countries, as a consequence of several factors, among them, the practice of a limited expert analysis that is not adequate to the international parameters that currently govern the determination of gunshot residues (GSR), which implies a considerable risk for the purposes pursued by the administration of criminal justice. In this regard, the opinion of a leading forensic expert has been consulted, as well as studies and articles of interest to the problem raised.