The book "Theoretical aspects of the academic discipline preliminary investigation in the Department of Internal Affairs . The textbook”, created by the team of authors, is a unique work that will become an indispensable assistant for law students, graduate students, as well as practicing specialists in the field of law enforcement . This manual not only generalizes theoretical knowledge, but also immerses the reader in the practical aspects of the preliminary investigation, which makes it relevant and in demand in the modern educational process. This book discusses in detail the key aspects of the preliminary investigation in the internal affairs bodies, including its goals, objectives and methods. The authors emphasize the importance of preliminary investigation as an integral part of the criminal process, emphasizing its role in ensuring the rule of law and protecting the rights of citizens. The reader will be able to learn about how to properly conduct an investigation, collect and analyze evidence, as well as how to interact with other participants in the criminal process. The book will be of particular interest to those who seek a deeper understanding of the mechanisms of law enforcement and wish to develop their skills in the field of criminology and criminal law. It is suitable for both students and young professionals who are just starting their career in law enforcement agencies. In addition, the manual will be useful to teachers who are looking for quality materials for the preparation of lectures and seminars on the discipline "Preliminary investigation" .. The topics raised in the book cover a wide range of issues related to the preliminary investigation. The authors analyze not only theoretical foundations, but also practical examples, which allows the reader to see how the theory is applied in real-life situations. Important attention is paid to legal aspects, ethical norms and modern challenges faced by investigators. This makes the book relevant in a rapidly changing legal environment and new security challenges. The style of the authors is distinguished by clarity and accessibility of the presentation, which makes it easy to assimilate even the most complex concepts. Each section of the book is structured logically, which makes it easier to find the necessary information. The authors use examples from practice, which helps the reader to better understand the material and see its application in real life. The team of authors working on this manual consists of experienced practitioners and scientists who have made a significant contribution to the development of criminal procedure and criminology. Their previous work has already proven itself in academia and among practicing lawyers, which adds additional value to this training manual. If you are looking for a high-quality and informative preliminary investigation manual that will help you not only in your studies, but also in your future professional activities, then “Theoretical aspects of the academic discipline preliminary investigation in ATS . This book will be a real treat for you.......... This is a book that will not only expand your knowledge, but also inspire you to further study law and criminology. Do not miss the opportunity to immerse yourself in the world of preliminary investigation and learn about its intricacies and nuances - this book is waiting for you!