Running amok in Malay, or spree killing in US, or beserking in Norse, is hardly a new phenomenon, and not confined to any single culture. Following a period of depressive or dissociative brooding, an individual arms themselves and embarks on a series of killings and attempted killings. It may be a single episode of violence if the weapon is an edged blade or suchlike - where the perpetrator is immediately proximate to the act, and can be himself killed or restrained - or over a longer period using a firearm if the perpetrator can evade immediate capture. Women never run amok; it's always men. Raoul Moat, the Washington sniper, Thomas Hamilton, Anders Breivik are just a few recent cases. And now Mohammed Merah in Toulouse.
The trigger for this behaviour can be anything from an unjust parking ticket to a sophisticated ideological self-delusion, a bad divorce, a bollocking from the foreman. You simply can't predict it. Yet governments will continue to want to try; they prefer to understand these mentalist episodes as 'lone wolf terrorist attacks' and search for group memberships and affiliations. Der Spiegel falls straight into this trap today, declaring "A man like Mohammed Merah is Western law enforcement's worst nightmare. The suspected perpetrator of the Toulouse attacks fits into the "lone wolf" category of terrorist."
But law enforcement agencies feel obliged to be responsible for such events happening, and always respond with "If only ...". If only we had access to everyone's emails, twitter posts, nectar cards, bus tickets, dvd rental records, radio listening habits, web surfing histories they say, we could better predict such behaviour. But of course they can't. Where the trigger can be as minor as a Kiwi barman short-changing them, leading them to assault the whole of Earl's Court with a samurai sword you can just never predict it.