The File of Young Kindaichi (1997 ) Episode 9

Hajime accuses Detective Akechi of being the murderer, but Akechi proves that he is not Redrum, and reveals that he is on the trail of a 30 year old crime. Hajime finds a ring in the fireplace and deduces that Redrum is actually the mystery novel writer, Kahoru Takigawa. She confesses to the murders because the three people she killed were responsible for the death of her lover, Kyoji Sayama, 29 years ago during a disagreement after the five of them carried out a large robbery.