At the scene of Song Jinfu's murder, due to the crime scene being meticulously cleaned, Lu Chuan initially did not find many clues while conducting the crime scene investigation.
Fingerprints were cleared, footprints were cleared, and tire tracks were cleared, leaving nothing at the scene.
The only harvest was some sea sand left on the mop used by the killer to clean the scene.
As the only clue discovered at the scene, Lu Chuan analyzed the sea sand on the first day.
Haizhou City has a relatively long coastline, with ocean to the east and south.
In other words, you can easily find sea sand anywhere.
However, in terms of the composition analysis of sea sand, there are some differences in sea sand composition in different regions.
For instance, the south of Haizhou City has some soft beaches, suitable for swimming and tourism.
The sand here is relatively soft and fine.
