Widespread appearance of possession, carrying and use of blank/gas pistols and revolvers in committing crime in the Republic of Serbia, every day puts police on new temptations and the new challenges. In this paper we presented legal frameworks which closely regulate the position of such weapons in the current Law of the Republic of Serbia. Herein is explained what is meant by the blank weapons, such as the threat of his (mis) use, what type of ammunition used in these weapons and what are dilemmas put before the participants in the criminal proceedings. Also, it is conducted an assessment the possibility of identification such weapons and ammunition, having in mind the specifics of their design and production. Keywords: blank/gas weapons, blank ammunition, gas ammunition, the law of Republic of Serbia, criminal identification.