A security guard reported a break-in at a warehouse. He claimed he was knocked unconscious from behind as soon as he opened the front door. Detective Fox checked the guard's uniform and immediately knew he staged the crime. What did Fox see?
The guard's uniform
The back of the guard's uniform jacket was covered in thick warehouse dust, but the front was clean. If he had been struck from behind upon opening the door facing forward, his back wouldn't have been pressed against a dusty surface beforehand unless he was lying face-down on the floor himself.
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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