Catching Sparrows

Pure reasoning, no supernatural powers. What is the connection between the murders two years ago and the current serial killings? A series of hunting for the Jianque organization, cicada, praying mantis, sparrow, shrike, who is the person standing at the top of the pyramid? What kind of butterfly effect will the tragedy of human traffickers cause in many years? Two years later, my sister fell to her death in the same place where her younger brother fell to her death. Can people really redeem themselves?