In a discussion over at Crooked Timber, Rich Puchalsky posted a link to a long post by Randall Collins, a sociology professor at U Penn: Clues to Mass Rampage Killers: Deep Backstage, Hidden Arsenal, Clandestine Excitement. Among other things it develops a sharp contrast between rampage killers and suicide bombers and has some very interesting remarks on the psychological difficulty of killing people face-to-face and what rampage killers do to overcome that difficulty.
In mass rampage killings, the killers are not aiming at particular individuals at all. The victims are anonymous, representatives of a collective identity that is being attacked. Hence mass attacks generally take place in institutional settings: mainly in schools, or work places, although recently also in exercise gyms and in churches. The Aurora, Colorado attack in July 2012 was unusual (or the harbinger of new settings), in a movie theatre; the Norway shooting attack of July 2011 was on a youth camp of a political party. The number actually killed is misleading; the attack is an effort to destroy an institution through the people who belong to it. In that sense it is a symbolic attack-- a deadly symbolic attack. The motivation and tactics of the mass killer are very different from most homicides; here it is not a matter of a personal grudge coming from ongoing conflict with a particular individual, as in the nearly half of all homicides which are among personal acquaintances; nor the targeted killing between gangs; nor the instrumental or accidental killings which take place in the course of another crime such as a robbery or rape. Most other types of homicides are impulsive or emerge from escalated situations; mass rampage killings are elaborately planned in advance.
The psychological difficulty of killing:
Any kind of violent confrontation is emotionally difficult; the situation of facing another person whom one wants to harm produces confrontational tension/fear (ct/f); and its effect most of the time is to make violence abort, or to become inaccurate and ineffective. The usual micro-sociological patterns that allow violence to succeed are not present in a rampage killing; group support does not exist, because one or two killers confront a much larger crowd: in contrast, most violence in riots takes place in little clumps where the attackers have an advantage of around 6-to-1.Another major pathway around ct/f is attacking a weak victim. But in almost all violence, the weakness is emotional rather than physical-- even an armed attacker has to establish emotional dominance, before he can carry out effective violence. One might think this is simply a matter of using a gun or displaying a weapon, which automatically puts the armed person in the position of strength, the others in a position of weakness. Nevertheless, detailed analysis of incidents and photos of armed confrontations show that groups without guns can emotionally paralyze an armed opponent, preventing him from using his weapon.Guns provide emotional dominance when an armed individual threatens a peaceful group and they try to hide or run away. This depends on the style of the victims. When rival street gangs clash, they do not turn their backs; they are used to gesturing, with and without guns, and most such face-to-face confrontations wind down. Running away has the effect of confirming emotional dominance; it is easier to shoot a person in the back than in the front; and turning away or attempting to hide one's face has the effect of removing one's greatest deterrent-- eye-contact with the opponent. Thus the hundreds who piled on the floor in the theatre at Aurora, or who ran from the attacker on the Norwegian island, may have saved some percentage of themselves; but they collectively could have saved more than ended up being killed or wounded, if they had used their superior numbers to confront the attacker. I don't mean just the possibility of physically overcoming him, but taking advantage of the fact that groups are always emotionally stronger than individuals, if they can keep themselves together and put up an emotionally united front: they could probably have made him stop shooting.If this sounds implausible, consider how rampage shootings usually end: in a 1997 school shooting at Paducah, Kentucky, the solo killer, a 14-year-old boy who opened fire on a prayer group in the school hall, allowed a teacher and the prayer leader to come up to him and take his gun away as soon as he had shot 8 girls and boys (who were facing away from him).
How rampage killers differ from suicide bombers:
There's much more.The suicide bomber kills him/herself at the same moment as the victims; this has the advantage of not seeing the carnage one has made. Suicide bombers are usually idealistic individuals who believe in a cause, and have never engaged in violence before; so the tactic is ideal for keeping any notion of violence out of their mind-- the most successful pathway is to keep one's mind focused on the normal details of routine activity, or on one's ideological message .... But rampage killers are obsessed with their attack; they want to see the token representations of the hated institution die. A minority of rampage killers commit suicide, but only after they have experienced the process of killing that they have fantasized about for so long.Motives and rituals of confrontation also affect the weapons they use. A remote bombing attack-- where the attacker places a bomb at the target and detonates it later from a safe distance-- does not fit the psychological scenario the rampage killer seeks. Disgruntled students often fantasize about blowing up the school, and this is perhaps their most common form of rebellious rhetoric; but it is entirely verbal ritualism (and circulation of a cultural cliché), since virtually all mass killings in schools have been carried out by shooting rather than bombs. And this is so even though many of the killers collect an arsenal which includes bombs; for instance the two killers at Columbine High School in 1999 brought nearly 100 explosive devices, and managed to explode 8-to-10 of them, but caused all their casualties by shooting. It appears that bombing is not sufficiently confrontational for the psychological scenario that a mass institutional killer seeks.Suicide bombers belong to an organized group, a movement with a long-term goal that they hope to advance, beyond the deaths of individual contributors; whereas rampage killers engage in purely personal revenge. Why this should affect the scenarios they choose? Suicide bombers have an abstract agenda; rampage killers are persons who have been personally humiliated. What they want is to reverse the scenario that has dominated their lives-- being looked down upon by others in that institution; the habitually dominated seek a moment of dominating others. This fills their horizon; the rampage killer rarely plans what happens next. In all his elaborate planning, he has made no plans for escape. The mass killing is the final, overwhelming symbolic event of his life.
See also this post Administering torture to others does "moral injury" to the torturer.