The core puzzle of the case is the lack of a single footprint around the body, despite it being in the middle of the garden, making it appear to be an "impossible crime".
: Despite the body being in the middle of a freshly raked sand garden, there is not a single footprint leading to or from the corpse. The Motives
(水流るる石庭の怪(前編)), originally aired in Japan on June 10, 2002 Episode Summary
Episode 282 Plot Summary: The Mystery of the Water-Flowing Stone Garden (Part 1)