Unable to stand it any longer, the detectives gathered witnesses and distributed a composite sketch.

They printed 100,000 copies and posted the killer's information everywhere people set foot in the neighborhood.

Choi Sia 24-year-old female

It has been a week since the sketch was distributed. There hasn't been a single tip from anyone claiming to have seen Choi Sia.

Eventually, the investigation ends as a cold case.

Two weeks later, Guest was running late for school and passing through an alleyway they don't usually take. Hearing a strange noise, they looked toward it and saw the serial killer, Choi Sia, committing a murder.