an extensive literature
1. Purely reactive: In order for a homicide to be rated as purely reactive, there had to be strong evidence for a high level of spontaneity/impulsivity and a lack of planning surrounding the commission of the offense. Reactive violence was coded if there was evidence for spontaneity or impulsivity, a rapid and powerful affective reaction prior to the act, and no apparent external goal other than to harm the victim immediately following a provocation/conflict. A clear example of a purely reactive homicide is if an unknown victim verbally insulted the perpetrator, who in a rage immedi- ately started a fight and proceeded to stab the victim to death with a weapon of “convenience” (e.g., a broken bottle in a bar).
2. Reactive/instrumental: To qualify for this rating, the homicide had to show evidence for both reactive and instrumental violence. However, the primary quality of the violence leading to death had to be reactivity. For example, using the example above, the reactive/instrumental description would apply if after or during the unplanned fight (and eventual murder), the perpetrator elected to rob the victim as well. Thus, the evidence would suggest that the homicide was unplanned/reactive but that there was also a secondary instrumental, opportunistic component.
3. Instrumental/reactive: To qualify for this rating, the homicide had to show evidence for both instrumental and reactive violence. However, the primary quality of the violence leading to death had to be instrumental. For example, an instrumental/reactive homicide would be coded if the offender started to commit a bank robbery but in the process proceeded to murder a bank teller after becoming agitated when the teller picked up a phone. In this case, a crime occurred for an obvious external gain, and the homicide was part of this instrumental act. However, the homicide occurred as a reaction to unplanned events within the context of the crime.
4. Purely instrumental: For a homicide to be rated as purely instrumen- tal, the offense had to have been clearly goal-oriented in nature with no evidence of an immediate emotional or situational provocation. The ho- micide had to have been committed for a clearly identifiable purpose other than “hot-blooded” spontaneous anger or a response to an immediate frustration. Therefore, a purely instrumental homicide was coded if there was strong evidence that the homicide had been intentional, premeditated (nonimpulsive), motivated by a clear external goal such as drugs, money, to obtain sex or revenge, and not immediately following a potent affective reaction. For example, an offender may have carefully planned, carried out, and concealed a homicide in order to steal from the victim. We also examined this issue categorically to test whether the psychopaths and nonpsychopaths had engaged in primarily reactive (rating of 1 or 2) or instrumental violence (rating of 3 or 4).
Instrumental violence was then classified further according to the fol- lowing categories: primary instrumental violence and secondary instru- mental violence. Instrumental violence was identified as primary when its main purpose was to inflict harm on an individual (e.g., revenge) and not to serve some other purpose such as material gain (e.g., drugs, money). In contrast, instrumental violence was considered secondary when the main purpose was not to inflict pain on the victim but to achieve a clear goal (e.g., drugs, money), and violence was committed only as a means by which to achieve these goals. Indeed, it should be noted that although we relied heavily on Cornell et al. ‘s (1996) original coding scheme, after an extensive literature review we decided to include planned revenge/ retribution as a potential type of instrumental aggression. This was meant to reflect the growing concern of researchers that instrumental violence, although planned and nonimpulsive, sometimes is committed primarily for
the purpose of inflicting pain and harm on another person and that “hostile” aggression also should sometimes be viewed as instrumental (e.g., Bush- man & Anderson, 2001; Indermaur, 1996; Tedeschi & Felson, 1994). Therefore, if there was a “cooling off” period, or a discernible gap in time between the provocation/frustration and the homicide, revenge/retribution was coded as an instrumental motive. Further, the various motivations that the offenders may have had for committing an instrumental homicide were investigated. Specifically, the possibility that the instrumental violence had been committed (a) for monetary gain, (b) drugs/alcohol, and/or (c) re- venge/retribution, (d) to obtain nonconsensual sex, or (e) for an idiosyn- cratic reason was recorded. A homicide was not coded if the motive or rationale for committing the homicide could not be determined or if it was not possible to ascertain whether the homicide had been spontaneous or planned.
