He described his serial murders as an " act of benevolence " . Child killer Kaoru Kobayashi described himself as " the next Tsutomu Miyazaki or Mamoru Takuma " . Miyazaki stated , " I wo n't allow him to call himself ' the second Tsutomu Miyazaki ' when he has n't even undergone a psychiatric examination . " Minister of Justice Kunio Hatoyama signed his death warrant and Miyazaki was hanged on June 17 , 2008 . The unusual swiftness of his execution as well as its timing soon after the Akihabara massacre prompted questions regarding the two incidents ; the Ministry of Justice had no comment . Ryūzō Saki said , " His trial was long " and that he was " not willing to criticize Hatoyama "
Akihabara massacre
Akihabara massacre
Tsutomu Miyazaki