"The Four Hundred Suspects" -- heh. Think of all those interviews. You'd have to bring in Holmes, Poirot, Nero Wolfe, Kojak, Peter Wimsey, Perry Mason, etc. and divide the list among them.
Let's see, who could those 400 be?
1. a carpenter who likes to pound nails in rhythm to the "Anvil Chorus"
2. a German immigrant who hates Wagner and loves Verdi
3. a hairdresser who plays The Barber of Seville as background music in his salon
4. Clayton Moore's grandson who can never hear the William Tell overture too many times
5. a wedding consultant who uses The Marriage of Figaro as her theme music
6. a liquor store owner who has rigged the cold case where the beer is stored to play the "Champagne Aria" every time the door is opened