A man serving a jail term for the attempted murder of a female high school student was arrested Wednesday on suspicion of killing a 9-year-old girl in 2004 in western Japan.

While Kunihiko Katsuta, 39, admitted to strangling Yukiko Tsutsushio, a third-grade elementary school pupil in Tsuyama, Okayama Prefecture, he denied his intent to kill the girl, and also denied stabbing her, police said.

Local police believe Katsuta choked and stabbed her to death at her home between 3:15 p.m. and 3:35 p.m. on Sept. 3, 2004. He is suspected of stabbing her multiple times with a knife, which is yet to be found.

Katsuta told investigators that he had never met with the girl before the incident, according to the police.

The police began questioning Katsuta in September as he emerged as a potential suspect after they expanded the search area and scrutinized crimes with similar tactics.

(Katsuyoshi Tsutsushio with a photo of his daughter Yukiko in August 2010)

Earlier in the day, the police transferred Katsuta from a prison in Okayama Prefecture to police cell for questioning and raided his home in Kakogawa in neighboring Hyogo Prefecture for clues as to his motive.

The girl was found bleeding on the floor of her home by her sister, who returned home at about 3:35 p.m. on the day of the incident.

She was taken to hospital with multiple injuries to her chest and abdomen, but was pronounced dead shortly afterward.

Katsuta was arrested in 2015 for stabbing a female junior high school student in the stomach with a knife on a street in Himeji, Hyogo Prefecture.

At the initial trial, the Himeji branch of the Kobe District Court noted in its ruling that Katsuta had developed an interest in animation while at high school and a taste for seeing girls' shirts soaked in blood, which later grew into an urge to stab girls in the abdomen.

The Osaka High Court subsequently sentenced him to a 10-year prison term in 2016.

In 2010, Katsuta was also sentenced to four years in prison for assaulting and injuring five girls on a street, including elementary and high school students.