Really feels quite a bit earlier than the 50s and the cheap film stock doesn't help matters any. It's not just that though. The plot itself reminds me of 30s films, as does the soundtrack. I know I recently said this about a previous film I watched but this is very Edgar Wallace, Maybe I only feel that way because I've been reading him lately but then again his impact on mysteries and thriller since the 20s is not only undeniable but prodigious.
This is quite an entertaining little film, falling squarely into the Mystery/whodunit genre and not really veering anywhere towards noir or even thriller. So it's good but quite safe. I'm thankful there's not too much comedic relief, as there often is with films of this kind, but it isn't dark or energetic either. A solid middle of the road mystery film.