When both the police and the public become aware that a serial murderer has begun a series of homicides, one of the primary concerns is the length of time the offender remains free in the community. As such, the longer a serial murderer is active, the deeper the sense of panic is felt among the community. Drawing from the criminal career perspective, in particular, the criminal achievement concept, the duration of a homicide series may be seen as a direct measure of the serial murderer's longevity; a proxy signal of their level of criminal achievement. The empirical study of serial murder has been undertaken only relatively recently and has coincided with the availability of databases designed to capture details about the offender's homicide series (e.g., Campedelli & Yaksic, 2021; Quinet, 2011; Yaksic, 2015). But even after decades of study using both qualitative and quantitative methods, few researchers have questioned what factors directly influence the duration of the serial murderer's homicide series and, in turn, their criminal achievement.
Attaining longevity extends beyond amassing a victim count that may earn the serial murderer the title of ‘prolific’. The number of victims is secondary to the serial murderer's need to remain undetected and unconfined. Thus, it is assumed that criminal achievement can be distilled down to merely being free to kill for as long as possible. To accomplish this form of criminal achievement is a substantial effort, one more difficult in the modern age than in the heyday of serial murder (Yaksic et al., 2019). The study of what constitute a serial murderer's criminal achievement is difficult because it is not possible to catalog the traits of uncaught serial murderers who have reached the extreme end of longevity.
The criminal achievement concept has been used to explain factors associated with offending productivity, or the ‘successful criminal’ in which the focus was to examine the: 1) payoffs/rewards from crime, and 2) cost/detection avoidance (Bouchard & Nguyen, 2010; Lussier & Beauregard, 2011; Tremblay & Morselli, 2000). Within the context of serial murders, the payoffs or rewards from committing these crimes may be reflected in the number of victims or in the fulfilment of the offender's motivation. More relevant to the current study, is the operationalization of criminal achievement in terms of the offender's ability to minimize cost or avoiding detection throughout the commission of the murder series.
Serial murderers are distinct from non-serial murderers primarily because these offenders attempt to avoid suspicion while carrying out homicides repeatedly over time (James & Proulx, 2016; Pakkanen, Zappala, Bosco, Berti, & Santtila, 2015). Serial murderers are generally referred to as efficient killers given that they continually escape apprehension. But, in their endeavors to remain free to fulfill their objective, serial murderers encounter both fortuitous circumstances and environmental obstacles.
Therefore, a balance between factors, both within and outside of their control, enhances their chances of attaining criminal achievement. As Shanafelt and Pino (2012) proclaim, contingency, accident, and choice all play a role in serial murder. James and Beauregard (2020) also note that situational factors can nullify precautions. Guided by the criminal achievement concept, the aim of this study is to explore factors associated with the duration of a serial murderer's killing series by examining offender, victim, and crime characteristics that can contribute to its longevity.
Early research identified certain behaviors – planning of offenses, targeting of strangers, controlling the victim with restraints, and hiding of the body – thought to enhance the likelihood that a serial murderer would be ‘organized’ and therefore be better at avoiding detection (Ressler, Burgess, & Douglas, 1988). Although the prevailing belief that so-called ‘organized’ serial murderers are effective at sustaining persistent careers has contributed to their legend (Hodgkinson, Prins, & Stuart-Bennett, 2017; Walters, Drislane, Patrick, & Hickey, 2015), research in recent years instead supports the notion that serial murderers prosper due to conscious learned strategies. These include premeditation and predation on vulnerable victims. First, serial killings are generally preceded by premeditation (Adjorlolo & Chan, 2014; Brantley & Kosky, 2005; Harbort & Mokros, 2001; McNamara & Morton, 2004), and sometimes followed by efforts to delay or avoid arrest (Beauregard & Martineau, 2014b; Chopin, Beauregard, & Bitzer, 2020; Salfati & Bateman, 2005). Additionally, insufficient planning contributes to cases being solved more easily (Balemba, Beauregard, & Martineau, 2014). Second, the degree to which a serial murderer's plan impacts the duration of the ‘cooling off’ period and the pre-selection of homicide locations, which provide safety for the serial murderer and little opportunity for the victim's escape, may lead to longer or shorter homicide series (Reale, Beauregard, & Martineau, 2017; Sorochinski, Salfati, & Labuschagne, 2015). Finally, efficient serial murderers make rational choices and weigh many factors simultaneously in their assessment of opportunity when seeking victims to kill (Chopin et al., 2020; James & Beauregard, 2020). As in any other crime, some individuals are better at this process than others. Serial murderers are generally in control of the death location and use their physical environment to create opportunities for murder, particularly in dense urban spaces that provide them with anonymity for the means to kill (Brookman, Maguire, & Maguire, 2019; DeFronzo, Ditta, Hannon, & Prochnow, 2007; Hodgkinson et al., 2017; James & Beauregard, 2020; Lynes, Kelly, & Uppal, 2019). These environments may influence the serial murderer's decision-making regarding how to dispose of bodies (Sorochinski et al., 2015). While body disposing and non-body disposing serial murderers make conscious decisions equally in choosing the location of the crime depending on their sophistication, time, and effort (Morton & McNamara, 2005; Synnott, Bakker, Ioannou, Canter, & Van der Kemp, 2019), some will use deliberate strategies offering the least amount of evidence (Mott, 1999). These strategies include moving the body to delay or avoid recovery as a method of detection avoidance (Reale & Beauregard, 2019), concealing the body (Beauregard & Martineau, 2014b), or leaving the body outside and exposed to the elements. Other serial murderers leave their victims “as is” after their death as a means of minimizing the chance of leaving evidence behind (Morton, Tillman, & Gaines, 2014). Each of these tactics hampers forensic analysis, disrupts investigations, and leads to longer kill periods, thereby making cases harder to solve (Quinet, 2011).
Victimology also influences how vigorously police work to solve homicides—what Beauregard and Martineau (2014b) call ‘victim preferencing’. Studies have shown that demographic characteristics such as race and ethnicity influence how individuals spend their time, which impacts risky lifestyles and routines, and in turn affect their exposure to crime and victimization (e.g., Lauritsen, & White, N. A., 2001; Peguero et al., 2013). The criminal opportunity theory has been used to explain the disparities in violent victimization across different racial groups, wherein minority individuals living in socioeconomically disadvantaged areas were more likely to be exposed to risky lifestyles (Cohen, Kluegel, & Land, 1981; Hindelang, Gottfredson, & Garofalo, 1978). Studies have suggested that criminal opportunities were often exploited in socially disorganized neighborhoods due to the lack of social guardianship and informal surveillance thereby, increasing the risk of victimization (Bursik, & Grasmick, H. G., 2001; Schreck, Wright, & Miller, 2002; Spano & Nagy, 2005). In the context of criminal opportunity, some serial murderers target sex workers, the homeless, drug abusers, runaways, transients, or other marginalized populations because they understand that the victim's social status can influence the attention garnered from investigators (Brookman et al., 2019; Reale & Beauregard, 2019). These victims are less likely to be reported missing, which can cause homicides to remain unsolved (Mott, 1999; Quinet, 2011). Even if reported, police may not place marginalized victims on a priority list (Lee & Reid, 2018). These choices in victim characteristics can enable serial murderers to continue killing for longer periods of time because the police have more difficulty linking the crimes to one offender, or they may simply not prioritize these cases.