One of the important means of proof is evidence obtained by an expert in the framework of expert activities in the process of forensic identification. The expert brings to the information channel special information from the field of science and technology, by means of which the primary information signal is transcoded into another kind of information signal, which will be available to the addressees of the taking of evidence. The theory of forensic identification is a learning of the general principles of identification of various objects in order to obtain criminalprocedural and other evidence. When formulating conclusions about identity, respectively formal logic is used to determine group affiliation. The conclusions must be clear, concise and comprehensible.