This article is devoted to the description of the experience of the volunteer activities of lecturer groups of the Ryazan branch of the V. Kikot Moscow University of the Ministry of the Interior of Russia. Peculiarities of forming professional psychological and pedagogical competencies of law students and cadets of universities the Ministry of the Interior, while giving public lectures, are illustrated. Cadets study in details the subject on which they are going to speak to schoolchildren, study their psychological and age characteristics, psychology of public speech, the basics of eloquence. Future lecturers do some kind of test run in front of other cadets, after that they have the possibility to analyse their own mistakes righting wrongs. While real public lectures, cadets study to speak in front of various categories of audience: in front of a group of several people, one school grade or in a full assembly hall. Lectures on the same topic can be held for students of different ages and for different categories of children: for students of ordinary schools, boarding schools, gymnasiums and lyceums; for law-abiding children and for those who are registered by juvenile departments. The article shows how giving public lectures in a lecturer group can form the professional competences of a law enforcement officer.