A priceless diamond was stolen from a glass case in an empty room. The only footprints in the dusty room belonged to the museum guard, who was found tied to a chair. Security footage showed no one entering or leaving the room through the locked door or windows. How was the diamond taken?
The ceiling vent / Air duct
The guard staged the robbery, entering through the overhead air conditioning vent, stealing the diamond, and then tying himself up to appear as a victim, leaving no floor tracks other than his own.
About this riddle
Detective riddles are tiny mysteries. Look for the detail in the story that does not fit; it is usually the clue that solves the case.
Difficulty: Hard. More like this: Detective riddles with answers or try Truth & Lie Island for a different kind of puzzle.
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