Shinji Aoba, who was sentenced to death over the July 2019 arson attack on a Kyoto Animation studio, has withdrawn his appeal, finalizing the ruling, sources said Tuesday.

According to the Osaka High Court, Aoba, 46, withdrew his challenge on Monday against the Kyoto District Court ruling that found him guilty. He was convicted of murder and other charges in the attack against the animation powerhouse, known as KyoAni, that left 36 people dead and 32 injured.

The defense side had submitted last September a document stating the reasons for the appeal, according to informed sources.

It also submitted an opinion by an expert different from the doctor who had conducted a psychiatric examination of Aoba following his indictment. The opinion argued not against the result of the examination but against the district court's evaluation of it.

The defense had planned to plead not guilty in the appeal.

In the lay judge trial at Kyoto District Court, the defense had argued that Aoba was in a state of insanity or had diminished capacity due to delusional disorder at the time of the incident.

The court ruled in January last year that the defendant was fully competent to take criminal responsibility although he came to bear a strong grudge against KyoAni due to the influence of the disorder. It also considered the severity of the attack in sentencing him to death.

Aoba and his lawyer appealed the ruling to Osaka High Court. According to a family member of a victim who met him, the defendant said he filed the appeal because he would not be able to talk otherwise.

According to the ruling, Aoba set fire to KyoAni's No. 1 studio in Kyoto on July 18, 2019, destroying the building and killing or injuring most of the 70 employees inside.