Hwaseong serial murders

Police in South Korea link convicted murderer Lee Chun-jae to the serial rapes and murders, which occurred between 1986 and 1991 and left ten dead. The investigations inspired the movie "Memories of Murder" and saw 21,000 people investigated. Lee, who is serving life for the 1994 rape and murder of his sister in law, cannot be prosecuted despite a DNA link to three victims because the statute of limitations has expired.

Notorious serial killer 'found' after 30 years

Sources:  BBC News