He may also have been your common or garden nutcase, or your standard loser.
Some of the folks he killed may have been too. I used to see all kinds of vaguely kiddie pr () n-omatic-like rpg programs in Akihabara. Last time I was there, I saw a 7-floor (count 'em, 7) building apparently dedicated entirely to underwear and Sailor Moon costumes.
*sigh* Just sad.