Second in the mystery series of films based on Stuart Palmer's stories of schoolteacher and amateur detective Hildegarde Withers and police inspector Oscar Piper, Murder On the Blackboard is an entertaining whodunit with fine moments of humor. Edna May Oliver, as Withers, makes the film. Her gaunt figure and comically overzealous snooping turn what would have been a routine murder mystery into a delight. The mystery itself is more of an excuse to show her in action; one of the film's flaws is its uninspired solution.