Jiang Yuan did not proceed with the autopsy in the normal order but began by carefully collecting trace evidence from the wound on the chest.
When the murderer killed, they used a lot of force, and the dagger moved very quickly, stabbing into the victim's heart and swiftly penetrating until the hilt hit the chest of the victim.
At the same time, the front blade of the dagger also touched the victim's rib, leaving a mark as seen from the dissection.
In this way, the victim's wound likely contained trace evidence of the murder weapon. Whether this evidence would help solve the case was not yet certain, but it was most likely useful for court evidence.
Actually, nailing a murderer was not that easy. Without sufficient evidence, courts often handed down reduced sentences. This was especially true in death penalty cases, where the demands for evidence and the chain of evidence were exceptionally high.