"Po Yun" Fan - Who Is the Murderer?

Well-known corporate executives and young girls died tragically one after another, and their ring fingers were chopped off after death. Who is the real culprit in this case? [The new "Ghost Debt Collection" next door is now open. OOC apologizes, the private setting belongs to me, the original work of "Broken Cloud" by Huai Shang. [This is purely for practice, please do not increase the height. Mission: Fight crime without delay