Re-Conceptualizing “Cooling-Off Periods” in Serial Homicide

Abstract

Cooling-off periods have been described as the state of returning to the offender’s usual way of life between homicides (Burgess, 2006) and are a crucial factor in defining serial homicide (Douglas, Ressler, Burgess, & Hartman, 1986). If the clinical aspect referring to the offender’s emotional and motivational state is removed, these episodes can be aptly termed time intervals between homicides. Factors such as geography, victim selection, and the offender’s level of social involvement may instead serve as more appropriate starting points for studying this concept. In the present study, these factors were examined using 16 series containing 90 time intervals with a reported median interval length between events of 34.5 days.

Cooling-Off Periods among Serial Killers

“…The most recent definition of serial murder has described the cooling-off period thus: "the murders are committed as discrete event(s) by the same person(s) over a period of time" (Adjorlolo & Chan, 2014, p. 490). As a result, new notions of short (less than two weeks) or long (more than two weeks, months, or even years) intervals between murders have become accepted in interpretations of serial murder (Osborne & Salfati, 2015; Schlesinger, Ramirez, Tusa, Jarvis, & Erdberg, 2017).…”

“…Others have argued, however, that this psychological explanation is too abstract and have, instead, proposed other functions of this period of time. For example, Osborne and Salfati (2015) claimed that the geographical preference and selection of the victim or social involvement of the murderer influence the intervals between the murders (Greswell & Hollin, 1994;Hickey, 2002).…”

“…Thus far, there is no statistical baseline or empirical research that clearly shows which factors directly influences the length of the cooling-off period. On the other hand, the cooling-off period has been found to be universal, thus proving that it has some latent function (Osborne & Salfati, 2015), in other words, it either enables or facilitates the next murder (Douglas et al, 2006;Douglas et al, 1986;Edelstein, 2014;Homes & Holmes, 1998;Levin & Fox, 2014;Morton & Hilts, 2008).…”

“…Existing research on the cooling-off period. The debate over the explanations for the cooling-off periods convinced scholars of the need to study it in further depth without attributing psychological, sociological, or other theories (Osborne & Salfati, 2015;Simkin & Roychowdhury, 2018). While some research has been conducted, there is, however, still no empirically-supported theoretical explanation.…”

“…Not all scholars have approved the neglect of the theoretical aspects. Of the few studies attempting to better understand and predict the cooling-off period, only one took into account variables such as the geographical distance between murderer and victim as influencing the interval until the next murder, and none addressed psychological explanations (Osborne & Salfati, 2015). An additional problem with the existing studies is their use of different operational definitions of serial murder.…”