During a blackout, a jeweler was robbed. The thief took a single ruby pendant from a velvet tray. When questioned, the security guard swore he saw the suspect through the pitch-black window wearing night-vision goggles, grabbing the ruby with his left hand, and running north. Detective Reed let the guard go and arrested him for the theft instead. Why?
The guard could not see in the dark
The guard claimed he saw the thief through the window during a pitch-black blackout. However, glass reflects light and does not allow someone inside a dark room to clearly see outside without an external light source, exposing the guard's lie.
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: Medium. More like this: Detective riddles with answers or try Truth & Lie Island for a different kind of puzzle.
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