KYOTO—Shinji Aoba, perpetrator of the worst postwar mass murder in Japan, was sentenced to death on Jan. 25 for killing 36 people in an arson attack at a Kyoto Animation Co. studio in 2019.

The role of Aoba, 45, in the murders was never in question during his trial at the Kyoto District Court. He admitted to the attack and nearly died himself in the fire that he started at the studio.

However, his defense team argued that he should be acquitted by reason of insanity or be shown leniency because of the mental and physical exhaustion he suffered.

Presiding Judge Keisuke Masuda said the court found Aoba was fully responsible for his actions, and that he was “neither insane nor of unsound mind” when he murdered all of those people.

The trial, conducted under the citizen judge system, ended with a sentence of capital punishment.

“The crime of pouring gasoline on victims and setting them on fire is as atrocious as it is cruel,” the judge said. “The horror felt by the victims is immeasurable.”

According to the ruling, Aoba broke into the first floor of the No. 1 Studio of Kyoto Animation, known as “Kyoani,” on July 18, 2019. He had prepared a supply of gasoline in advance, poured the fuel at the entrance of the building, and set it on fire.

Workers were trapped in the three-story studio as the fire spread. Thirty-six people, including Kyoani employees, died and 32 others were injured.

The defense argued that Aoba was “delusional” at the time of the attack.

He believed that Kyoani had stolen his ideas for a novel, and that he harbored a strong resentment toward the company by contrasting its success with his own failures, the defense team said.

The court did acknowledge that a delusional disorder influenced Aoba’s thought process for his claims against Kyoani.

But the court said he was not delusional when he planned the attack and carried it out.

The court pointed out that Aoba had expressed sympathy for the man who was executed for committing a random killing spree in Tokyo’s Akihabara district in 2008.

Aoba had planned an indiscriminate killing at Omiya Station in Saitama Prefecture about a month before the Kyoani arson attack, the court said.

For the Kyoani attack, Aoba studied previous crimes and chose the “arson-murder” method.

“(The murder plan) was due to his aggressive personality, his way of thinking, and his knowledge, and it was not influenced by his delusions,” the court ruled.

The court also noted that Aoba had hesitated for more than 10 minutes near the crime scene just before setting the fire. That indicated he knew his actions were wrong.

“It can be said that he could have dissuaded himself from committing the crime,” the court said.

The court noted that Aoba considered when to commit the crime based on information from a Kyoani documentary, and that he was “acting consistently” with a premeditated murder plot, including being prepared with gasoline and other supplies.

The defense said Aoba “has been at the mercy of his delusions for more than 10 years.”

His lawyers said he was delusional not only about Kyoani stealing his work but also about “being followed by security police who are under the direction of a ‘dark figure.’”

The court dismissed this argument.

“It remains possible that his ability to distinguish between right and wrong and his ability to dissuade himself from committing a crime were somewhat impaired, but it cannot be said that they were significantly impaired,” the judge said.

Aoba was taken into custody on a street near the studio shortly after the fire broke out. He had severe burns all over his body and fell unconscious.

He underwent repeated surgeries to save his life, and he gradually recovered. After about 10 months of hospitalization and treatment, he was arrested.

At the first hearing of his trial in September 2013, Aoba admitted to the charges against him.

“At the time of the incident, I thought I had no choice but to do this,” he said. “I did not expect so many people would die, and now I think I went too far.”

For the sentencing session on Jan. 25, Aoba was pushed in his wheelchair into the courtroom wearing a navy jersey.

He bowed his head toward his defense team and looked at the gallery.

When the session opened, the presiding judge asked Aoba if he had something he wanted to say.

After a few seconds, Aoba replied in a small voice “No, I don’t.”

Many of the victims’ bereaved family members attended the session seated behind prosecutors or in the gallery.

After the judge handed down the death sentence, Aoba bowed his head and left the courtroom with a blank expression on his face.

Bereaved family members in the gallery wiped away tears.