Prof. Dr. Zeljko Nikac born on November 27, 1959. in Belgrade, Republic of Serbia, citizen of RS. He finished elementary school, XII Belgrade Gymnasium and the Faculty of Law in Belgrade. Labor-legal status: work experience in the profession over 35 years, in civilian and police (1991) - OUP Palilula, SUP Belgrade, MUP RS and KPU (VŠUP, KPU). He completed specialist training for criminal operatives, a special human rights course for members of the police, and was repeatedly praised and awarded for his results. Important duties in the RS MUP: Deputy and Head of the Department for Control of Legality of the SUP Belgrade (2003-2006), Assistant Chief of the Police Directorate of the RS MUP (2007-2009), by the rank of police colonel and in the title of chief police advisor. At the end of 2009, ie at the beginning of 2010, he was permanently employed at the Criminal Police Academy. He was vice-dean for scientific research (2009-2012), now a teacher at KPU. Scientific research work: he was a teacher at VŠUP in the subjects Criminology (2001-2005) and Criminalistics Operations (2005-2007). Research Associate at the Institute for Criminological and Sociological Research in Belgrade (2005), Assistant Professor (2006), Associate Professor (2009, 2013 - re-election) and Full Professor (2016) KPA. He was previously involved in KPA research projects: "International Police Cooperation" (2007), "Community Policing on Juvenile Delinquency" (2008) and Project Manager of "School Violence and its Suppression" (2009-2011). Currently a participant in KPA projects - external projects through MPNTR and internal project.