When Viktor had to leave town for a few days, he had no one to watch his penguin, so he called the "district militiaman" and asked him to check on him while he was gone.
What, exactly, was a "district militiaman"?
It's "участковый" in Russian, a shortened designation of "участковый инспектор милиции" - local police inspector (=district police officer, local policeman). Note that "militia" is a term used in soviet time for "police", and it is still used in some post soviet countries.
From Russian wikipedia (translated from Russian):
The district police officer is an official of the police..carrying out official activities aimed at protecting the rights of citizens living in the corresponding administrative-territorial area, as well as citizens who have suffered from criminal encroachments on the specified territory.