Three Hildegarde Withers mysteries:
PENGUIN POOL MURDER (1932)
MURDER ON THE BLACKBOARD (1934)
MURDER ON A BRIDLE PATH (1936)

There were six Hildegarde Withers movies made between 1932 and 1937, average-budget programmers featuring a "spinster" schoolteacher who just happens to get caught up in murder investigation in which she manages to outwit the police, specifically Inspector Piper. Though both of them are rather cold and brittle, an affectionate relationship develops between them. Three actresses played Hildegarde over the years, though the inspector was always played by James Gleason. By far, the best was Edna May Oliver, who introduced the character in PENGUIN POOL MURDER. After some choppy scenes of exposition, we catch up with Hildegarde and her grade school class on a field trip at a New York City aquarium, where a dead body is found in the penguin pool. The efficient Miss Withers is on the case right away, helping to nab a purse snatcher (who may or may not have something to do with the murder) and keep track of clues for the inspector. The somewhat convoluted plot involves the possible financial ruin of the aquarium director, and an affair between the dead man's wife (Mae Clarke) and another man (Donald Cook). After the lovers are arrested, Clarke's lawyer (Robert Armstrong, the explorer in KING KONG) gets involved, but it takes the unstoppable Hildegarde to sort out the real clues from the red herrings. The plotting and characterizations feel like second-rate Agatha Christie, but Oliver and Gleason make the movie worth seeing.

At the end of PENGUIN, Withers and Piper get engaged, but in the following movie, MURDER ON THE BLACKBOARD, they are just casually dating. In this one, a music teacher is found dead at Hildegarde's school. Suspects include the teacher's roommate (Gertrude Michael) who is secretary to the old but lusty principal (Tully Marshall), and Michael's boyfriend (Bruce Cabot) who had dated the dead girl in the past. There's also a drunken janitor who gets around the school building through secret passages, but he's too obvious a suspect to be the the real villain. Oliver and Gleason remain good reasons to watch; other cast members include Regis Toomey, Jackie Searl, and Gustav von Seyffertitz as a crime lab technician (shades of CSI). The best line: when Hildegard tells the inspector, "Stop acting like a movie detective!" BRIDLE PATH is a later entry in which Helen Broderick takes over the role of Miss Withers, and as much as I like Broderick in other films, like TOP HAT and THE BRIDE WALKS OUT, she can't fill Oliver's shoes. The plot involves murder among the upper crust as an heiress is found dead on a horse riding path in Central Park; suspects include her ex-husband, a stable boy, and a man who was sweet on the dead girl's sister. The opening and closing are good, but the middle is rough going and Broderick is just too colorless in the central role. Zasu Pitts also played the character, but I haven't seen either of her films. [TCM]