“Are you trying to suggest that the person who poisoned Judy might have left fingerprints on the thermos cup? Indeed, as Long as the police use professional equipment to do the fingerprints feature extraction and matching, I believe that the criminal will be soon found."

This was not the first time that Elma had drugged someone, so she was well aware of the removal of fingerprints.

She carried in her bag a bottle of cream that resembled ordinary hand cream. But it was some type of special wax.

Once it was applied to the fingertips, one could feel free to touch anything without leaving any fingerprints behind. And this kind of wax dried up and fell off easily.

Just now, Elma had quietly rubbed her hands behind her back and wiped off all the wax that had been applied to her fingertips. Plainly stated, there were only Rylee's and Judy's fingerprints on the cup.