Jang Kyung-chul

 "I don’t know what pain is. Fear? Don’t know that either."

- Jang Kyung-chul

Jang Kyung-chul is a serial killer and bus driver in I Saw the Devil who terrorized the city, murdering women and children by raping them with a blade. After he kills his latest victim - Joo-yoon Jang, who was daughter of former police officer and pregnant at time of her death, her fiancee and father of her unborn child, Kim Soo-hyun, tracks him down for revenge.

Kyung-chul tired raped woman-twice one of his victims was a schoolgirl whom he kidnapped and a nurse whom he forced her to do oral sex while he on run both women are saved by Soo-hyun.

He had a teenage son named Sang-won, whom he abandoned and sent living with his parents (Soo-hyun secretly visited them), and he was best friends with Tae-Joo, who was also a serial killer along with his girlfriend Se-jung who cheated on him with Kyung-chul before Soo-hyun attacks them. Later Kyung-chul discovered that a device which Soo-hyun put in his mouth was inside his body, and attacked Joo-yun's father and raped and killed her sister Soo-yun. when he revealed to Soo-hyun after that Kyung-chul ready surrendered to police he was suddenly dragged by Soo-hyun's car and put execution when Joo-yun was killed. at final confinement when Soo-hyun asked to Kyung-chul why he killed women and girls caused their loved ones are in agony. he said that he enjoy it as Soo-hyun leave and covered his ears at same time his parents and Sang-woon come to visited him to open the door Kyung-chul begged not opened but he got decapitation‎ which shocked his family what he did to Joo-yun's family.

He played by Choi Min-shik