The tutorial provides a brief description of the Astra Linux operating system and LibreOffice office suite, as well as some special programs from the open source series. The manual also discusses specialized software used in the activities of law enforcement agencies. To develop practical skills, the manual contains tasks with detailed instructions for their implementation. The textbook is intended for educational and methodological support of the educational process of students in educational institutions of higher education of the system of the Ministry of Internal Affairs of Russia, it can be useful to a wide range of readers.