The Kidnapper

In the 2007 South Korean true crime/thriller film Voice of a Murderer, the events of the film are caused by''' the Kidnapper. ''' The story where the Kidnapper appears in is based on an unsolved kidnapping case which occurred in South Korea, 1991 in which the unidentified suspect sadistically taunted the child's parents for 44 days demanding ransom. The kidnapper in the movie is just as sadistic as the real-life criminal he's based on thus being faithful to the tragic story.

The Kidnapper is portrayed by famous actor Kang Dong-won.

Voice of a Murderer
The Kidnapper kidnaps 9-year-old Hang sang-woo from his apartment's playground late at night and almost immediately makes the ransom demand to his parents - 100 Grand, no cops or their child dies. When the understandably upset and overtly concerned mother secretly reports it to police when her husband goes to the ransom drop, he unwittingly blows the assigned undercover officer's cover and the kidnapper changes the ransom drop to another day.

Similar circumstances, rotten luck on the police officers part, and perhaps cruel fate makes the parents seeing their son again more unlikely as days turn into weeks and the kidnapper shows no emotion except for sadistic glee and condescension with sarcastic politeness. The kidnapper seems to know the parents and police every move while the police fail to comfort the parents or find clues to the kidnapper's identity other than his chilling voice. At one point he kidnaps the detective in the father's trunk during a supposed botched ransom drop and beats him up before leaving him naked tied to a pole under heavy rain to mock the police and parents. He even continually refuses to let his family know if their son is alive than a second-long pleading of Sang-woo. When his demands aren't met when he wanted it, he even pulls out one of Sang-woo's teeth and mails it to his mother.

One of the investigators on the case eventually discovers Sang-woo's pleading is from a tape recording.

On the final day of the soul-crushing journey to get Sang-woo back, he (Kidnapper) demands Sang-woo's father to come to a fair with 200,000 Grand but he sneakily grabs the money and vanishes.On the 44th day Sang-woo's body is found discarded near the Han River with the kidnapper with his ill-gotten fortune - 300 Grand and gone.

Real-life Case
The Kidnapping of Lee Hyung-ho

In 1991 9-year-old Lee hyung ho was kidnapped near by home. The kidnapper made nearly a hundred phone threats to Lee's parents demanding around 100,000 dollars as ransom while sadistically taunting them and evading police investigators and traps in a span of forty-four days. During this time no one knew the kidnapper murdered Lee 2 days after kidnapping him.

Lee was found in a sewer near his home in a box over a month since his disappearance.

This case reached news headlines and public outrage at the time and is one the top 3 most infamous crimes committed in South Korea, alongside the Hwaseong Murders and the Frog Boys. The investigation into the boy's seemingly senseless murder was undeniably unsuccessful and by 2006, 16 years since the boy's murder the Statue of Limitations closed the case which further inspired the director to make the film after years of deliberating on doing so. Though, however, the film's promotions met some criticism for its incredibly emotionally charged trailers which was deemed as "A studio exploiting a terrible tragedy for commercial purposes.". The film also started a movement called "Let's Catch the Bastard!" (referring to the kidnapper of Lee) which lasted from 2007-2008 but was rather unfruitful. However, hope remains for Lee's family as Korea scrapped the law on first-degree murders as of 2015.