Japanese police on Wednesday formally charged 42-year-old local man Shinji Aoba with murder relating to the arson attack in July last year at Kyoto Animation.

The blaze, set using gasoline, killed 33 people on the scene and three more in hospital. A further 33 were injured.

The charges include murder, attempted murder, arson, trespass and breach of the arms-control law, the Kyoto prosecutor’s office said.

Aoba was himself burned and was arrested quite quickly after the shocking attack. He appeared to make a confession in which he said he was angry with the firm for stealing some of his ideas. The firm often known as KyoAni, operates a competition soliciting draft novels, but has consistently denied that it used Aoba’s.

Police in Saitama, near Tokyo, uncovered DVDs from Kyoto Amination when they raided Aoba’s home. They have also investigated Aoba as the source of anonymous threatening messages made against the company in 2018. The sender reportedly used the Tor identity-disguising software.

Before charging Aoba, however, police were obliged to wait first for him to partially recover from his injuries. Then, as Aoba has a history of mental illness, they had to wait a further six months for him to undergo psychological evaluation.

Despite the tragedy, KyoAni went ahead with the September 2019 release of “Violet Evergarden: Eternity and the Auto Memories Doll,” a “side story” film from the studio’s “Violet Evergarden” film and TV franchise. The planned January release of its “Violet Evergarden: The Movie,” was pushed back to April and then postponed again due to the coronavirus. The release eventually went forward in September and earned some $19 million in Japan.