Sorry for the poor English. There is a serial killer (male) in the movie who always makes the victim's face a clown face by using a red lipstick. There is also a doctor (female), whose husband is having an affair with a young girl. The doctor killed the girl and made her face a clown face by using a red lipstick, aiming at making the others think that it was the serial killer who killed the girl. Nevertheless, the detective (male) figures out that the girl was killed by the doctor rather than the serial killer, because the serial killer always makes his victim a crying clown face, while the doctor made the girl a smiling clown face. Both the serial killer and the doctor are arrested, but the serial killer shows his respect to the detective.