The death toll in last week’s arson attack on a Kyoto Animation Co. studio rose to 35 Saturday after a man being treated at a hospital died, police said the same day.

Some of the people injured in the incident are still hospitalized. The police have not released the identities of any victims.

Investigators have yet to question the suspect, Shinji Aoba, who has severe burns and remains in serious condition. He is suspected of entering Kyoto Animation’s three-story building on July 18 and igniting gasoline.

Investigators searched Aoba’s home in the city of Saitama on Friday for clues that might point to a motive.

Investigative sources said confiscated evidence included items such as a DVD produced by Kyoto Animation, a smartphone and a badly damaged large speaker. It is the first confirmation of an item that links the suspect and Kyoto Animation.

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An investigation is underway to track the history of his smartphone usage to determine the motive for the suspect’s actions, sources said.

Aoba is said to have claimed when he was captured following the attack that he set fire at the studio because the company stole his novel. However, there are no records of Aoba trying to have a novel be made into anime by Kyoto Animation, called KyoAni by fans of the genre, according to the company.

The police have yet to serve an arrest warrant on Aoba on suspicion of murder and other offenses as he is in intensive care with severe burns at a hospital in Osaka Prefecture.

Aoba has been unconsciousness since the attack but has recently started to show subtle responses, sources said. Still, a senior Kyoto police official said the suspect’s life remains in danger.

According to different investigative sources, the animation studio received repeated email threats from the same internet address between last September and November. Some of them were addressed to specific employees, they said.

The sender of the emails used anonymous communication software called Tor, which makes the tracing of senders difficult, they said.

Meanwhile, a fundraising drive for Kyoto Animation has raised substantial donations from around the world. A lawyer for Kyoto Animation said it had received about 30,000 money transfers to its bank account by Friday amounting to about ¥620 million.

An internet crowd funding effort by U.S. distributor of Japanese animation had also raised more than $2.28 million (¥247 million) by Sunday.