On September 20, 2018, the sister of a victim filed an injunction to the Seoul Central District Court to ban the screening of the film, complaining that the production crew did not asked for permission before making a story about the murder of her brother. The family were also upset that the film only changed the story's setting to 2012 (the actual murder case happened in 2007), and that some elements in the film bears great similarity to the actual case, such the convict's age and his murder method.
The Korean title of the film is Amsu-salin, meaning "Unknown Murders".
On September 27, 2018, the family member of another victim shared a post on his social media account and drew media's attention. He showed support for the release of Dark Figure of Crime, reasoning that the film will bring attention to unreported crimes.
The film was selected as the opening film of the 3rd London East Asia Film Festival, held from October 25 to November 4, 2018.
Principal photography began on August 14, 2017 in Busan, and finished November 6, 2017.