According to TBS News, the hacker, who recently caused multiple false accusation cases by remote operation of virus-infected PC, sent emails hinting suicide to TBS and lawyers. The email said that he made a mistake during the series of the cases and he will hang himself. Four people including the assistant director of Gundam 00 were arrested for false accusation. Police reported that the hacker used Tor to hide his identity but he forgot to use it once when he made a post on 2channel.

An image file was attached to the email from the hacker and it showed a figure of Madoka Magica surrounded by a LAN cable.

The image of Madoka figure attached to the hacker's email

Source: TBS
Related topics:
Assistant Director of Gundam 00 Released on Possible False Accusation
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Update Feb 10th
According to Sankei Newspaper, Tokyo Metropolitan police has arrested a 30 year old PC engineer for sending threatening e-mails and messages to multiple places by hacking other people's PC. He had once been arrested and imprisoned for a different online threatening case in 2005. He confessed that he was falsely accused in the case in 2005 and he wanted to revenge on the police and prosecutors.

Source: Sankei