Japanese police arrested a 45-year-old man on suspicion of stabbing an elementary school girl in Hyogo Prefecture, western Japan, 18 years ago.

Katsuta Kunihiko is serving a life sentence for the murder of another elementary school girl in Okayama Prefecture in September 2004. His conviction became final last year.

Investigative sources say he is suspected of attempting to kill a fourth-grade girl in Tatsuno City in September 2006. The girl was returning home from school and was seriously injured.

The case remained unsolved due to lack of witnesses and evidence.

Since the method of the attack was similar to that of the Okayama case, Katsuta was voluntarily interrogated and reportedly admitted his involvement in the Tatsuno City attack. Sources say what she told police was consistent with the girl’s injuries and the circumstances surrounding the incident.

Katsuta also reportedly confessed to his involvement in the fatal stabbing of a 7-year-old girl named Unose Yuzuki in Kakogawa, Hyogo, in 2007.

Police plan to question Katsuta further to uncover details of two unsolved cases.