A pretty young music teacher is bludgeoned to death in Hildegarde's school, where she's reunited with Oscar, but the autopsy report says she was dying from poison too.
Plot keywords (from IMDb): alarm clock, alcohol, alibi, amateur sleuth, anemia, ant, attempted murder, benzene, blackboard, blood, bounced check, brooklyn bridge, cellar, chemistry lab, concussion, confession of crime, coroner, corpse, criminal, dead body, death, detective, drunk, drunkenness, dumb cop, dysfunctional marriage, elementary school, false accusation, female detective, fire escape, forensics, furnace, german american, gossip, gun, hatchet, hildegarde withers, hit on head, homicide, hospital, inspector, interrogation, irish sweepstakes, janitor, jealousy, liquor, lottery ticket, manhattan new york city, manipulative female, marital infidelity, medical examiner, mislaid trust, motive, murder, murder confession, murder investigation, new york city, old maid, pick axe, picking a lock, poisoning, police inspector, police sergeant, principal, prison escape, radiator, rare disease, reference to abraham lincoln, reference to henri landru, reference to martha washington, reference to sherlock holmes, romantic rivalry, schoolteacher, science teacher, scream, secret, secret door, secret marriage, sequel, shoe, snoop, snooping, solving a mystery, spinster schoolteacher, straw, student, suicide, sweepstakes, sweepstakes ticket, turning off the lights, warehouse, whistling, music teacher
Murder on the Blackboard (1934) [IN PROCESS - Information may be incomplete or contain inaccuracies]