Tokyo: The motive behind the arson attack at an animation studio in the Japanese city of Kyoto which killed 33 people a day earlier, may have been the theft of ideas, the media reported on Friday.

The 41-year-old man apprehended for the Thursday attack, Japan's worst mass killing in 18 years, at a three-storey studio of Kyoto Animation Co. in western Japan was identified by the police as Shinji Aoba.