Gas, Inspector Palmu!

A wealthy old religious patron raises a disobedient and mentally disturbed niece - until she all of a sudden drops dead as the result of a murder made to look like an accident. A grouchy, elderly superintendent and his young and overly enthusiastic assistant are called in to investigate. And there is a lot to look into, since the deceased had few friends, but many enemies. Almost everyone seems to have not only a motive but also something to hide... (imdb)