章 159: Chapter 154 Footprints

The dust fixative purchased by the Ningtai County Bureau was made using a solvent of alcohol mixed with rosin.

It's quite an old-fashioned fixative; its transparency is slightly poor, and the drying and fixing time is long.

Jiang Yuan sprayed a row of fixative in the stairwell; the footprints in the back were clearly visible only after those in the front had been gradually sprayed.

At this point, an ordinary crime scene investigator or trace examiner would typically sprinkle some powder to reveal the prints. Jiang Yuan didn't need this step; he just looked at the footprints and savored their originality.

But he only took a brief look.

Most of the footprints were likely left by the security guards.

The security guards at Wanghe Building all wore leather shoes and small ties—they were not very practical, but they looked quite official.