An antiques dealer was murdered in his shop. A shattered hourglass lay beside him on the Persian rug, its sand spilled out in a small heap. The shop's front door was locked from the inside with a deadbolt. Detective Vance noticed that the sand in the bottom bulb of the hourglass was completely dry, but the top bulb had a faint ring of moisture inside. He immediately suspected foul play involving a freezer. How?
Frozen sand trick
The killer likely mixed water into the sand of the upper bulb and froze it solid, then placed the hourglass upright. As the ice slowly melted in the warm shop, the sand began to trickle down, creating a delayed timing mechanism to establish an alibi for the exact moment of death.
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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