komesar

1. commissioner
   Evropski komesar za proširenje stiže u Beograd. — The European Commissioner for Enlargement is arriving in Belgrade.
   Komesar za izbeglice obišao je kolektivni centar. — The Commissioner for Refugees visited the collective centre.
2. (in the police) police commissioner; police inspector
   Komesar je ispitao sve svedoke. — The inspector questioned all the witnesses.
3. (historical) commissar
   Moj deda je bio politički komesar u partizanima. — My grandfather was a political commissar with the Partisans.

In the police sense it usually refers to foreign police systems (France, Italy, Germany etc.), most often in translated books and films; the Serbian police has no such rank. The English equivalent depends on the country: commissioner, inspector, superintendent.