Abstract: The research subject is the essence of investigation and intelligence characteristics of crimes from the viewpoint of forensic science and the theory of investigation and intelligence activities. The research object is social relations emerging in the process of detection and investigation of crimes, theoretical substantiation and law-enforcement practice revealing the essence, components and parts of the mechanism of formation of investigation and intelligence activities. The author considers the correlation between theory and practice of forensic science and investigation and intelligence activities, and the feasibility of use of the term «investigation and intelligence characteristics of a crime». Based on the study of different opinions of the leading researchers in the field of forensic science and theory of investigation and intelligence activities about the definition of the essence, contents, classification and elements of the concept of «investigation and intelligence characteristics of a crime», and using different methods of scientific cognition, the author considers the feasibility and legitimacy of use of the esencial definition and its practical application. The main conclusion of the research is based on the viewpoints of well-known scholars, who have divided into two opposite camps. The representatives of one deny the concept under study, while the others, as well as the author, prove their opinion and state that the concept «investigation and intelligence characteristics of a crime» exists in the theory of investigation and intelligence activities. The author attempts to substantiate the feasibility of this definition. 

Abstract: The research subject is the legal status of individuals confidentially assisting law enforcement bodies (confidential informants). The decisions of the European Court have significant impact on the perfection of Russian legislative system and law enforcement practice, particularly on the use of information obtained from confidential informants. The content of article 17 of the Federal law “On operational investigations” doesn’t contain any specification of individuals confidentially assisting law enforcement bodies and doesn’t comment on the admissibility of evidence obtained with their help.
The research methodology includes the method of comparative jurisprudence, which is used to study the legal status of confidential informants; the method of comparative analysis, which is used to define the possibility to assist operative units during operational investigations. The author studies the decisions of the European Court of Human Rights, the topical problems of law enforcement practice related to the legal status of confidential informants of law enforcement bodies. The scientific novelty of the study consists in the analysis of statutory documents regulating the legal status of confidential informants of law enforcement bodies; in the proposals about the improvement of legislation on operational investigations. The author concludes about the need to reformulate article 17 of the Federal Law “On operational investigations”. 

Abstract: The subject of the research is the particularities of legal regulation of operative investigative arrest as part of operative investigative activities set forth by Article 6 of the Federal Law No. 144 of 12 August, 1995 'On Operative Investigative Activity'. According to the author of the article, current legal grounds for arrest do not consider particular features of investigative unit activities which causes certain difficulties in the law-enforcement practice. Taking into account the practical orientation of performing operative investigative arrest or seisure in the process of operative investigative activity, it is necessary to note that legal acts regulating this activity lack standards that would regulate the procedure, grounds and conditions and other aspects of applying operative investigative arrest or seizure. Based on the author, these standards should be described and fixed in legal documents. The author has used the following research methods: comparative law method to analyse legal grounds for arrest or seizure; and comparative analysis method to define conformity of possible operative subdivisions in the process of operative investigative arrest. The author focuses on oustanding problems of law-enforcement practice assocaited with the implementation of such enforcement measure as operative investigative arrest or seizure by operative subdivision officers. The scientific novelty of the research is caused by the fact that the author conducts an analysis of legal acts regulating the procedure and grounds for arrest and offers recommendations on how to improve operative investigative activity. The main conclusions of the research are as follows: there is a need to amend Article 15 of the Federal Law 'On Operative Investigative Activity' with particular legal standards regulating the grounds and conditions, procedure, and limits of operative investigative arrest or seizure of suspects or other persons in the process of operative investigative activity.