Murder on the Blackboard is a 1934 American pre-Code mystery/comedy film starring Edna May Oliver as schoolteacher Hildegarde Withers and James Gleason as Police Inspector Oscar Piper. Together, they investigate a murder at Withers' school. It was based on the novel of the same name by Stuart Palmer. It features popular actor Bruce Cabot in one of his first post-King Kong roles, as well as Gertrude Michael, Regis Toomey, and Edgar Kennedy.

Plot

Miss Withers discovers the dead body of her colleague, music teacher Louise Halloran, in a schoolroom. She summons her old friend, Inspector Oscar Piper, but by the time he arrives, the corpse has disappeared. Having watched the only entrance (other than a fire exit with an alarm), Miss Withers knows the killer must still be inside. When the police search the building, Detective Donahue is knocked out in the basement. Meanwhile, Miss Withers notices various clues, including a tune on the blackboard in Halloran's classroom. The body is found being burned in the basement furnace. Then, the fire alarm goes off; the murderer has escaped.