Cooperative Murder?

"Yes, Bro Yu, these were the results provided by the handwriting expert!" Hu Bin, who was from the forensic department, told Zhao Yu over the phone, "He has already taken into consideration the deceased's position, height, strength and so on. They are a hundred percent certain that the deceased left an ice radical, which is a Chinese character with two strokes that looks like two drops of water...

"Alright, I got it! Hu Bin, I am just casually investigating right now. So, please keep this to yourself and tell the handwriting expert to keep his mouth shut, too!" Zhao Yu exhorted.

"Don't worry, Bro Yu! I won't!" Hu Bin guaranteed.

Zhao Yu then exchanged a few more words with him casually before hanging up.

By this time, the sky had already turned dark. Zhao Yu sat in his Landrover, switched on the light in his car, and started jotting down notes in his notebook.

This time, it is really getting more complicated...