It's an after-school killing with 'Murder on the Blackboard'

Murder on the Blackboard (1934)
Starring: Edna May Oliver, James Gleason, Gertrude Michael, Frederick Voeding, Bruce Cabot, Tully Marshall, Regis Toomey, and Barbara Fritchie
Director: George Archainbaud
Rating: Six of Ten Stars

Murder hits close to home when one of Miss Withers' colleagues (Fritchie) is bludgeoned to death in the school where she teaches. As she and her friend, Inspector Oscar Piper (Gleason) investigate, they learn that many of the school's faculty and staff had reason to commit the carefully planned murder.

"Murder on the Blackboard" is a fast-paced, bare-bones mystery film full of witty dialogue that wastes no time in getting going; operates with a minimum of characters--just enough to obfuscate the identity of the murderer but no so many to make the film feel overcrowded--and locations; and not a moment wasted with filler material or even subplots. (Well, there are a couple kinda-sorta subplots that tie directly into the solution of the mystery, but they are more accurately "stub-plots" they are so minor and barely developed.)

There was one big drawback to the economic nature of how this film was executed and that is that we didn't get any of the quieter moments that showed the mutual romantic attraction developing between Hildegarde and Oscar. I thought that was one of the more appealing aspects of the first film in the series, because it was unusual to see characters like these get to be anything but the gruff cop and frumpy old maid sleuth. All that's left in this film is a sense that they grudgingly respect each others intellect, despite their constant bickering. Also missing from this film is the chance for Oscar to show that he's actually a good cop and a solid detective... it's almost entirely Hildegarde's show and she solves the mystery all on her own.

Speaking of solving the mystery... I also found the "key clue" to be more than just a little far fetched. I can't really comment beyond that without spoiling the mystery, but I can't even imagine the notion that it was a clue occurring to anyone, let alone using it to zero in on the killer's identity... except in a case where the writer told the character to have the idea in the first place.

"Murder on the Blackboard," despite not being as good as "The Penguin Pool Murder", is entertaining  and well worth the roughly 70 minutes it will take you to watch it.