An article form Tokyopop:
http://www.tokyopop.com/444.html Firstly, 'Cartoonist' is SO f#cking insulting. It's MANGAKA or Writer or Illustrator.
It appears to be the writer that got arrested, not the mangaka.
Well, it seems to be a Katana and not really a knife... some says it's a knife some says it's a katana...
And if this goes on his works Hikaru no Go and Death Note may be taken off the shelf.