Wired has an interesting article on the psychology of political assassins. The US Secret Service has done a study of 83 people who killed, or attempted to kill, political figures. They found that the motivations for the killings were often mundane and obvious. And there was often a slow deterioration in the social and mental life of the assassin prior to the event, leading the service to develop early intervention methods.
Contrary to popular assumptions about public killings, the attackers didn’t conform to any particular demographic profile. But when Fein reconstructed their patterns of thinking, he was able to distill them into a handful of recurring motives for killing a public person — motives that seemed consistent regardless of whether a given individual was delusional or not (and three quarters of those who pulled the trigger were not).
Some hoped to achieve notoriety by killing a well-known person. Others wanted to end their pain by being killed by Secret Service. Still others hoped to avenge a perceived, idiosyncratic grievance unrelated to mainstream politics. Some hoped, unrealistically, to save the country or call attention to a cause. And some hoped to achieve a special relationship with the person they were killing.