Security footage appears to show the suspect in the deadly arson attack at a Kyoto Animation studio walking around the scene before the incident. Police suspect he was waiting for an opportunity to carry out the attack.
Police apprehended 41-year-old Shinji Aoba at the scene of Thursday's attack. He is being treated in hospital for burns.
Investigators learned that Aoba purchased gas cans, a pushcart and a lighter he used in the attack at a store about 5 kilometers south of the studio.
Footage taken by two security cameras installed at a building 600 meters north of the store captured a man resembling Aoba at around 11:15 a.m. on the day before the fire.
About five minutes later, another camera also captured the same man. The footage shows the man pushing a cart as he walks north slowly.
Aoba was also witnessed several times around the Kyoto Animation headquarters and another studio of the firm.
Police suspect Aoba traveled a long distance on foot with the pushcart containing gasoline canisters before he started the fire.
Aoba is a resident of Saitama Prefecture, north of Tokyo. Local officials say he was employed as a temporary worker for the prefectural government from 1995 to 1998.
He worked as a so-called mail boy, collecting and delivering mail and documents in the prefectural government buildings.
Aoba's former boss said he was diligent and communicated clearly. She said she thought highly of him.
She said he appeared to be a very honest young man, and that she never heard him talking about novels or anime.
She said it is very hard to believe that Aoba committed arson and she has no idea about his motive. She said she wants to know how he changed so much over the past 20 years.
Sources say they heard that Aoba worked at a convenience store and other workplaces after he lost his job when the local government outsourced the delivery work.