The article is devoted to the definition and justification of the criteria and indicators for sustainable future formation of professional law enforcement officers. The definition of the concept of «professional reliability» is given. The requirements to the selection criteria are proposed by different scientists. The requirements that must meet the criteria are highlighted; the relationship of criteria and indicators of professional reliability is shown. The criteria and indicators of formation of professional reliability are based on the analysis of the criteria and indicators that are close to the essence of such things as professional competence, professional competence and professional readiness of future police officers for professional work. Based on the opinions of the experts evaluation of the criteria of formation of professional reliability of future police officers are allocated. On the base of analysis the author identified motivation, knowledge-operational, personal and regulatory criteria for formation of professional reliability. The characteristics of each criterion of professional reliability, the identification of the indicators and levels of its formation are proposed. The indicators of student-regulatory criteria are the following professionally important personal characteristics such as mental stability, responsibility, discipline, commitment, perseverance, poise, self-confidence, self-esteem and self-control. The indicators of motivational criteria characterize the nature of the formation of future specialist to the profession of a policeman, the presence of a conscious desire for faithful implementation of professional activity and form the motives and needs of professional activities, the facilities responsible for its implementation, compliance with the law. Knowledge of the operational parameters of criteria is presented by professional knowledge, professional skills of professional activity (special tactical, psychological and vocational special), the level of physical fitness, weapons possession. Each of these indicators has three levels: high, medium and low. The noted criteria and indicators of forming of professional reliability of the future police officers of internal affairs are based on fundamental principles of systematic and structural approaches and divided into three conditional groups: criteria and indicators of the terms, process and effectiveness which enables to analyze forming of professional reliability of the police officers of internal affairs simultaneously as to the process and result.