Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
officer [ˈɔfɪsər] n (MIL) офице́р; (also: police officer)полице́йский*m adj (in Russia) милиционе́р; (of organization) заве́дующий*m adj
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.