I stared at the body in a daze when I felt Xiaotao nudge me, "I found some needle holes!"

She pointed out several other needle holes on the victim’s arm. Only one made it to the blood vessel while the others weren’t in the right place. The victim’s skin was swollen and inflamed. It seemed like these murderers weren’t skilled in intravenous injections and it took a long time for them to get it right.

"Could this be the cause of death?" asked Xiaotao.

I glanced at the victim's face reflexively. Unfortunately, her facial features were corroded and could provide no clues.

Thus, I proceeded to listen carefully to the victim's chest for a few minutes, then raised her arm and observed the blood vessels. Finally, I came to the conclusion, "It was the cause...