Flowers are stacked up at the site where the corpse of a murdered 7-year-old girl was found, in Niigata's Nishi Ward on May 14, 2018. (Mainichi)

NIIGATA -- Police are investigating the possibility a man arrested in connection with the murder of a 7-year-old Niigata girl, who was found dead along a railway here, planned her abduction, noting that he skipped work before she went missing.

The 23-year-old man, Haruka Kobayashi, was arrested on suspicion of abandoning and mutilating the corpse of the girl. He has reportedly admitted to murdering her, and told investigators that he used his car to transport her body and that he placed the girl's body on the tracks to fake a train accident.

The victim's body was found after being hit by a train on the JR Echigo Line in the city's Nishi Ward on the evening of May 7, a little over 100 meters from her home. Her caramel-colored backpack and sneakers were found in the area within a radius of several dozen meters.

Police suspect that Kobayashi may have planned the abduction, as she went missing while walking alone, within a distance of about 300 meters from her home.

In April 2018, police sent public prosecutors documents on Kobayashi over a separate case accusing him of violating a prefectural ordinance by performing indecent acts on a minor last year.

A representative of the electrical work company where Kobayashi worked said May 7 was the first time he had skipped work without notifying the company. He was in his sixth year at the firm and had been in charge of electrical work at buildings and factories.

Kobayashi is believed to have been denying that the incident was planned, telling police that he accidentally hit the girl with his car, but police have not been able to confirm that this was the case, and investigators suspect that this testimony is false.

Kobayashi drove around Niigata for several hours while keeping the girl's corpse in his car. As for the reason why, he was quoted by investigative sources as telling police that he "wanted to kill time."

The victim's corpse was abandoned between around 10:19 p.m. and 10:30 p.m. on May 7. From 10 p.m. to 11 p.m. only four trains run on the line's single track -- three fewer than during the previous hour. Kobayashi's home is only about 70 meters from the spot where the girl's body was discarded, and police suspect that he had been waiting until fewer trains were passing through the area.

Investigative sources said the girl had not been wearing her sneakers and that it was believed they had been placed next to her bag and her corpse before the train hit her.

The Niigata Prefectural Police headquarters on May 15 sent Kobayashi to the Niigata District Public Prosecutors Office on suspicion of mutilation and abandonment of a body.

(Japanese original by Aya Iguchi, Mei Nanmo and Hidenori Kitamura, Niigata Bureau)