Abstract
Sadistic offenders are often described as individuals who are forensically aware, who carefully plan their offenses, and preselect the location of their crime. Despite this emphasis on strategies to avoid police detection, no study has specifically examined whether this behavior or trait was specific to sadistic offenders. Utilizing a sample of 350 cases of sexual homicide from Canada, sadistic sexual homicide offenders (SHOs) are compared with nonsadistic SHOs on their investigative awareness. Results from logistic regression analyses show that sadistic SHOs are more likely to use various precautions to avoid detection and select a deserted location, in comparison with nonsadistic offenders. In addition, sadistic SHOs, despite having a lesser time to body recovery than nonsadistic offenders, are more likely to see their case remain unsolved. Implications for the assessment of sexual sadism as well as for the police investigations will be discussed.
Introduction
The prevalence of sadism is difficult to estimate due in part to the unreliability of the diagnosis and the fact that some criteria rely on self-report from the offenders themselves (Healey, Lussier, & Beauregard, 2013). But even more difficult to estimate is the prevalence of sadism within sexual homicide (Kerr, Beech, & Murphy, 2012). Sadistic offenders have been described in several studies (e.g., Beauregard & Proulx, 2002; Brittain, 1970; Groth & Birnbaum, 1979; Knight & Prentky, 1990; Marshall & Kennedy, 2003; Proulx, Blais, & Beauregard, 2006; Warren, Hazelwood, & Dietz, 1996) and have often received other labels, such as organized sexual murderer (Ressler, Burgess, & Douglas, 1988) or murderer motivated to carry out fantasies (Beech, Fisher, & Ward, 2005). These studies highlight the fact that sadistic offenders carefully plan their offenses, preselect the location of their crime, and prepare a rape-kit, which may include tape, handcuffs, rope, knife, and a gun. Moreover, sadistic offenders target their victims according to specific criteria related to their deviant sexual fantasies, most often vulnerable victims such as sex trade workers. If the victim is killed, the sadistic offender is more likely to transport and hide the body to prevent detection (Beauregard & Proulx, 2009).
Despite this emphasis on the careful planning of the offense and efforts to evade police detection, no study has specifically examined whether this behavior or trait was specific to sadistic offenders. In the current study, we test if the presence of investigative awareness is a distinctive feature of sadism.
Diagnostic Issues: A Move Toward Behavioral Crime Scene Indicators
Researchers often note the challenge in identifying sadism is due in large part to the varying definitions and diagnostic criteria found in key sources of reference. The International Classification of Mental and Behavioral Disorder, 10th edition (ICD-10; World Health Organization, 1992) and the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR; American Psychiatric Association [APA], 2000) are often acknowledged as key contributors to the problem of diagnostic variability. The ICD-10 for instance, uses the same diagnostic category for both sadism and masochism and describes the disorder as a sexual preference for activities involving the infliction of pain, humiliation, or bondage. Sadomasochism is presumed to be present in some degree in normal sexual life, and thus can only be diagnosed if it is the principal source of arousal or is necessary for sexual gratification. Conversely, the DSM-IV-TR assigns sadism and masochism to distinct diagnostic categories, where sadism in this context is described as involving “recurrent, intense sexually arousing fantasies, sexual urges, or behaviors involving acts (real, not simulated) in which the psychological or physical suffering (including humiliation) of the victim is sexually exciting to the person” (APA, 2000, p. 574). Moreover, the DSM-IV-TR requires these urges, fantasies, and behaviors to be acted on with a nonconsenting individual. In both the ICD-10 and the DSM-IV-TR, it is specified that the sexual fantasies, urges, or corresponding behavior must have been present for at least half a year and cause significant distress or social impairment in the individual. Thus, the lack of consistency in both criteria and the definition thereof is fairly evident in these two major resources for clinicians. 1
Concerns have also arisen regarding the reliability in the diagnosis of sadism. Nitschke, Mokros, Osterheider, and Marshall (2012) reported the results of seven studies that examined observer agreement regarding severe sexual sadism. They found that clinical agreement in diagnosing severe sexual sadism differed widely depending on the sample and methodology of the study. Nitschke et al. (2012) suggested that challenges in key diagnostic criteria in both the ICD-10 and the DSM-IV-TR are likely to play a role in the inconsistencies found. With the ICD-10, the reliance on sadism as the main source of sexual arousal or necessary for sexual gratification is particularly challenging to establish within forensic settings. This is due to the fact that it typically relies on self-reporting from the patient when other objective information is not available (Richards & Jackson, 2011). This is also true of the DSM-IV-TR, which requires the identification of sexual fantasies and urges to receive a diagnosis. Sexual sadism is also unique in the DSM-IV-TR as it is the only disorder that includes behavioral motivations as a diagnostic criterion (Richards & Jackson, 2011). This can be problematic however as information is oftentimes withheld or unavailable causing diagnosticians to make inferences in the sadistic motives from available evidence (Marshall & Kennedy, 2003; Nitschke et al., 2012). As a whole, sexual offenders are noted as not particularly forthcoming about their true sexual interests (Beauregard, Proulx, & St-Yves, 2007), which is usually even more salient in sexual sadists (Grubin, 1994). In situations where diagnosticians must infer a sadistic motive, this tends to result in an overreliance on aggressive or violent aspects (Marshall & Kennedy, 2003; Myers, Burgess, Burgess, & Douglas, 1999).
Much of the focus recently has been on identifying behavioral crime scene indicators of sadism, which can be scored utilizing a scale. This method is not intended to replace diagnostic criteria but is instead meant to offer alternative means for identification that can often be used in conjunction with the DSM-IV-TR and the ICD-10. Scale items typically focus on sexual and violent behaviors demonstrated by the offender at the crime scene. There is general agreement that the most important indicators of sadism are (a) that the offender is sexually aroused by sadistic acts, (b) the offender exercises power/control/domination over the victim, (c) the offender humiliates and/or degrades the victim, (d) the offender tortures the victim or engages in acts of cruelty, and (e) the offender mutilates sexual parts of the victim’s body (Marshall & Hucker, 2006; Marshall, Kennedy, Yates, & Serran, 2002; Nitschke et al., 2012). Research conducted by Mclawsen, Jackson, Vannoy, Gagliardi, and Scalora (2008) showed that a group of 60 clinicians were able to discriminate crime scene behaviors as sadistic or nonsadistic reliably. Specifically, they identified three types of behavior deemed to be the most clearly associated with severe sexual sadism: (a) the use of threats to evoke fear; (b) cutting, stabbing, strangling, biting, or beating the victim during the sexual assault; and (c) infliction of pain to sexual areas by the use of a physical object. In addition, Marshall and Hucker (2006) extracted behavioral items considered by clinical experts to be the most important in determining sadism and then weighted each item based on their recommended degree of relevance by a group of experts. Through this method, they formed a 17-item measure, based on crime-scene and police data. Offenders who score 11 or more on the scale are deemed as severe sadists. However, this study was criticized for its lack of evidence for meeting empirical psychometric standars, such as internal consistency and reability (Nitschke et al., 2012). In consequence, Nitschke, Osterheider and Mokros (2009) reproduced the scale with the inclusion of object insertion into a victim’s genitals and removed 7 items that did not meet reliability criteria. Using the sum score of 4 out of 11 items as the cutoff, their scale, called the Severe Sexual Sadism Scale or SeSas has shown to have a high degree of stability, reliability, reproducibility, and it perfectly distinguished between the sadists and nonsadists.
Inspired by the SeSaS, Myers, Beauregard, and Menard (2013) proposed the Revised Sexual Homicide Crime Scene Rating Scale for Sexual Sadism (SAD-SEX-SH-R) to identify the presence of sadism in sexual homicide offenders (SHOs). This scale includes the following eight items: (a) sexual domination of the victim through the use of bondage, asphyxia, blindfolding, and a knife; (b) physical or psychological torture of victim; (c) victim forced to verbally or physically engage in sexually degrading, humiliating behavior; (d) gratuitous violence, excessive injury, biting, cutting, or other acts of physical cruelty inflicted on the victim; (e) anal or oral sex forced upon victim; (f) use of an inanimate object to sexually penetrate the victim; (g) sexual mutilation of the victim; and (h) souvenirs or trophies taken from the victim. Similar to the SeSaS, the SAD-SEX-SH-R was able to identify sadism in a sample of SHOs. These studies (e.g., McLawsen et al., 2008; Marshall & Hucker, 2006) provide evidence of the utility of behavioral crime scene indicators to identify sadism.
Investigative Awareness
One particular aspect that has often been associated to the sadistic offender is his investigative awareness (Beauregard & Martineau, 2012). Some offenders take specific precautions before, during, or after the crime to decrease their risk of detection. This adaptation of their modus operandi has been associated with an evolving criminal sophistication on the part of the offender. Offenders who adapt their modus operandi to thwart police investigative efforts may be said to be exhibiting investigative awareness (Beauregard & Martineau, 2014). These actions suggest that the offenders possess knowledge or an understanding of police investigative practices and have developed strategies to avoid police detection. This should not be confused with forensic awareness (Davies, 1992), which is exhibited when an offender reveals knowledge or an understanding of the importance of forensic evidence (e.g., DNA, fingerprints, dental impressions) to police investigation through their behaviors or actions. Thus, forensic awareness is defined as the taking of additional steps and adapting the modus operandi used in a crime to hide evidence to ultimately avoid apprehension (Davies, 1992). Although useful, the concept of forensic awareness is often limited to the forensic evidence potentially present at the crime scene whereas investigative awareness encompasses all the strategies used by the offender—including forensic awareness strategies—to avoid police detection.
The Federal Bureau of Investigation (FBI) studies (e.g., Ressler et al., 1988) have suggested that the sadistic SHO is more likely to show investigative awareness and avoid detection by removing evidence from the crime scene or taking his weapon with him after the crime. In their descriptive study of 30 sadistic criminals, Dietz, Hazelwood, and Warren (1990) showed that these offenders typically exhibit investigative awareness as a majority of them had studied law enforcement procedures, wore gloves not to leave fingerprints, and had preselected isolated locations to commit their crime. Similarly, Gratzer and Bradford (1995) as well as Beech, Craig, and Browne (2009) showed that some of the offense characteristics associated with sadism included careful planning of the offense and the taking of the victim to a preselected location which provides safety for the offender and little opportunity for escape or rescue of the victim (see also Groth & Birnbaum, 1979; Hazelwood, Dietz, & Warren, 1992).
Despite the fact that sadistic offenders are often described as possessing investigative awareness and conscious of behaviors adopted to avoid detection, most of the studies mentioning this specific trait are either anecdotal or descriptive in nature. No studies to date have examined if investigative awareness is a distinctive feature of sadism. Considering that investigative awareness includes behaviors easily observable at the crime scene, it becomes important for clinicians and law enforcement to test whether this trait is statistically associated with sadism. Therefore, the current study will examine whether strategies associated with investigative awareness constitute a feature that can distinguish sadistic SHOs from nonsadistic SHOs.
Method
Sample and Procedure
The sample includes 350 cases of sexual homicide in Canada dating from 1948 to 2010. At the time of entry within the database, 250 cases were solved and 100 were unsolved. Solved cases include those in which the offender has been identified but may not have been charged or convicted for the offense. If there is more than one offender and not all have been identified, then the case is considered unsolved. Data was collected from a national database that is operated by the Royal Canadian Mounted Police (RCMP) for serious and violent crimes. Investigators assigned to each individual case were responsible for collecting the data and submitting within approximately 45 days into the investigation. Data related to the victim(s), the potential or suspected offender, the behavior of the offender during and after the crime, as well as any forensic information available are utilized in this study. To be considered within the current sample, all offenses had to be identified as completed (real incidences only, attempts are not included). The offense had to involve a sexual element, specifically, that there was evidence that the crime was sexually motivated or there was sexual activity. Using the FBI definition of sexual homicide, the case had to include at least one of the following: (a) victim’s attire or lack of attire, (b) exposure of the sexual parts of the victim’s body, (c) sexual positioning of the victim’s body, (d) insertion of foreign objects into the victim’s body cavities, (e) evidence of sexual intercourse, or (f) evidence of substitute sexual activity, interest, or sadistic fantasy (Ressler et al., 1988). In the current sample, 25.1% (n = 88) of the cases presented evidence of sexual activities at the crime scene other than vaginal and anal intercourse, while it was established that in 10.6% of cases (n = 37) postmortem sexual activities occurred. Biological evidence suggesting sexual activities between the offender and the victim was also present in 24.0% of the cases (n = 84).
Measures
Dependent variables
The current study seeks to predict the presence of sadism within the sample of SHOs. The SAD-SEX-SH-R created by Myers et al. (2013) is utilized to determine sadism within the current sample. This scale was chosen for its utility in determining sadism within SHOs exclusively. The behavioral indicators used with SAD-SEX-SH-R are similar to SeSaS, which has been tested for its reliability and reproducibility (Nitschke et al., 2012). All scale items represent behavioral crime scene indicators that involve sexual and violent elements. Scale items were coded dichotomously as 0 (= absent) or 2 (= present). 2 Offenders are scored across all eight items, and those that score a 6 or more are deemed to be sadists (Myers et al., 2013). Utilizing this method, the current sample indicates that 36.6% (n = 128) of SHOs are sadists and 63.4% (n = 222) are nonsadists.
Independent variables: Victimology
The current study examines a total of five variables related to victimology, all coded dichotomously (0 = no, 1 = yes): (a) victim is female, (b) victim abuses alcohol, (c) victim abuses drugs, (d) victim is a sex trade worker, and (e) victim is a street person/homeless. These variables were selected as previous studies have shown that sadistic SHOs typically target vulnerable victims (e.g., sex trade workers, homeless persons; Beauregard & Proulx, 2002; Beauregard & Martineau, 2014; Beech et al., 2009; Salfati, James, & Ferguson, 2008).
Independent variables: Locations involving risk of detection
When considering the risk of detection in sexual homicide, it is important to take into account the fact that some offenders choose the location where they commit the crime after having assessed the risk of detection associated with these locations. Previous studies have shown that sadistic offenders tend to select isolated locations to commit their crimes (e.g., Beech et al., 2009; Gratzer & Bradford, 1995; Groth & Birnbaum, 1979; Hazelwood et al., 1992). In the current study, a total of six variables related to locations involving risk of detection are included, all coded dichotomously (0 = no, 1 = yes): (a) risk of being detected at contact scene, (b) risk of being detected at offense scene, (c) risk of being detected at body recovery scene, (d) contact scene was deserted, (e) offense scene was deserted, and (f) body recovery scene was deserted.
Independent variables: Forensic awareness
The study examines a total of eight dichotomous variables (0 = no, 1 = yes) related to forensic awareness as defined by Beauregard and Martineau (2012): (a) any forensic awareness strategies used, (b) removing/destroying evidence (i.e., involves wearing gloves, using a condom, setting fire to or cleaning the scene), (c) disposing of victim’s body, (d) acting upon victim and/or the environment (i.e., consist of precautions taken by the offender such as threatening the victim not to report; disabling the lighting, telephones, security system, and/or the victim’s vehicle; administering a drug to the victim; tying the victim up; blocking access in and out of doors or windows; and killing the victim for the purpose of eliminating the witness), (e) other precautions taken (e.g., offender wearing a mask, attempting to disguise or alter their appearance, and changing residence after the crime, offender used a scanner to determine police activities, offender used a devise to alert them of anyone approaching, and/or using a lookout location where the offender could observe the scene without being noticed, covering the victim’s eyes, gagging the victim), (f) semen located, (g) other biological samples available for analysis, and (h) body moved. Studies have often suggested that sadistic SHOs are often forensically aware and take specific precautions at the crime scene not to be detected by the police (Beauregard & Martineau, 2016; Beech et al., 2009; Groth & Birnbaum, 1979; Ressler et al., 1988).
Independent variables: Detection avoidance
The study includes two variables examining the ability of SHOs to avoid police detection. The first variable looks at whether the case is unsolved (0 = no, 1 = yes), suggesting that the SHO is still at large and was never apprehended for the crime. The second variable is continuous and is measuring the number of days it took to recover the victim’s body after the sexual homicide. Research shows that the longer it takes to find a body following a homicide, the less chance to recover forensic evidence that could lead to the apprehension and conviction of the offender (Beauregard & Martineau, 2014).
Analytical Strategy
First, bivariate analysis was conducted with the independent variables and the dependent variable. Predictor variables that indicated statistical significance with the dependent variable were kept for multivariate analysis. Then, binary logistic regression was conducted on SPSS 20. Each grouping of variables (victimology, location, forensic awareness strategies, and detection avoidance) was introduced sequentially in separate models.
Results
First, bivariate relationships between sadism and each independent variable are examined. Table 1 indicates that nine out of 21 variables are significantly (or approaching significance) related to the offender being a sadist. SHOs targeting male victims are more likely to be a sadist. Moreover, SHOs are more likely to be a sadist when they use any forensic awareness strategies, they attempt to remove/destroy evidence at the scene, they act upon the victim and/or the environment for forensic awareness purposes, and use other precautions not to be detected by the police. Also, SHOs choosing to get in contact with the victim and release the body at a deserted location are more likely to be sadist. Finally, although only approaching significance, SHOs who see their case remained unsolved are less likely to be sadist. Sexual homicide cases in which it takes longer to recover the victim’s body after the crime are more likely to be committed by nonsadists.
Bivariate Relationships Between Victimology, Forensic Awareness, Locations Involving Risk of Detection, Detection Avoidance, and Sadism.
Note. FA = forensic awareness.
M (SD), F coefficient.
p < .10. *p < .05. **p < .01. ***p < .001.
Table 2 presents the results of the sequential logistic regression analyses predicting sadism. To obtain the most parsimonious model, only the variables that were found to be significant at the bivariate level were included in the logistic regression analysis. 3 Both variance inflation factor (VIF) and tolerance statistics were conducted to ensure that there were no issues with multicollinearity between predictor variables. Model 1 includes only the victimology variable of victim gender. As observed at the bivariate level, SHOs targeting a male victim are more likely to be a sadist (β = −0.33, p < .05). Model 2 examines the locations involving risks of detection while taking into account the victim gender. Similar to Model 1, SHOs targeting male victims are more likely to be a sadist (β = −0.91, p < .05). However, none of the location variables are significant. Model 3 examines forensic awareness variables while taking into account the victim gender and location variables. As observed in the previous models, SHOs targeting male victims are more likely to be a sadist (β = −0.95, p < .05). However, contrary to Model 2, both location variables become significant. Thus, SHOs who get in contact (β = 0.96, p < .01) and dump the body (β = 0.59, p < .05) at a deserted location are more likely to be a sadist. Moreover, SHOs who act upon the victim and/or the environment (β = 2.23, p < .001) and remove/destroy evidence (β=1.41, p<.001) at the scene to avoid police detection are more likely to be a sadist. Finally, Model 4 examines the detection avoidance variables while including the victim gender, location, and forensic awareness variables. Results show, as in previous models, SHOs who target male victims (β = −1.10, p < .01) are more likely to be sadists. Moreover, SHOs who get in contact (β = 1.20, p < .01) and dump the body (β = 0.66, p < .05) of the victim at deserted locations are more likely to be sadists. Also, SHOs who act upon the victim and/or the environment (β = 2.67, p < .001) and remove/destroy evidence (β = 1.85, p < .001) at the scene to avoid detection are more likely to be sadists. Interestingly, using other precautions to avoid detection becomes significant in the fourth model. Thus, SHOs using other precautions (β = 0.89, p < .05) are more likely to be sadists. Finally, SHOs who are able to avoid detection (β = 1.12, p < .001) are more likely to be sadists but these offenders see the victim’s body being recovered faster (β = −0.01, p < .05) than with nonsadists. Although the overall correct classification percentage is modest, it significantly improves from Model 1 (66.4%) to Model 4 (75.9%). Similarly, the Nagelkerke pseudo R2 indicates a significant improvement from Model 1 (2.5%) to Model 4, which indicated that 42.3% of the variance in the the dependent variable could be attributed to the joint effects of the independent variables.
Sequential Logistic Regression Predicting Sadism in SHOs.
Note. SHOs = sexual homicide offenders.
p < .05. **p < .01. ***p < .001.
Discussion
The study aimed at testing if investigative awareness is a distinctive feature of sadism in a sample of SHOs. As shown in our findings, SHOs are more likely to be identified as sadists when they use strategies to avoid detection. More specifically, sadistic SHOs are more likely to carefully preselect deserted locations to encounter their victim and dump their bodies. Moreover, sadistic SHOs are more likely to exhibit forensic awareness by acting upon the victim and/or the environment (e.g., disabling the victims telephone or car, or using police scanners to track police movement), destroying and removing evidence (e.g., cleaning or setting fire to the crime scene), and using other precautions such as staging the crime scene or protecting their identity. Finally, sadistic SHOs, despite seeing the victims’ bodies being recovered faster than nonsadists, are more likely to avoid police detection. These findings suggest that there may be underlying differences in motivation for SHOs and that sadism is not necessarily directly connected to sexual homicide. In particular, conclusions from prior research suggest that some SHOs are more likely to kill as the result of situational factors, rather than a desire to fulfill deviant sexual fantasies (Beauregard & Proulx, 2002; Beauregard et al., 2007; Kerr et al., 2012). Thus, it is possible that nonsadistic offenders had the intent to rape, not murder, but due to situational factors such as excessive resistance on behalf of the victim (Beauregard et al., 2007) took any means necessary to achieve their goal of sexual gratification. This is supported by research conducted by Beauregard and Proulx (2002) that defines two types of SHOs, those that are sadistic and those that are angry, wherein the sadistic SHOs have elaborate sadistic fantasies that are more important to them than actual reality, which lead them to be more likely to premeditate their crimes and act out the murder in a way that reflects their fantasies. The angry SHO on the contrary, does not have prior sadistic sexual fantasies, lacks premeditation, and kills based on provocation on the victim’s behalf. The findings indicate that investigate awareness may in fact be a distinctive feature of sadistic offending and provide evidence to suggest that they do differ from other SHOs.
It is also interesting to note that sadistic offenders were more likely to have male victims than nonsadistic offenders. Warren et al. (1996) found that in a study of 20 sexual sadistic serial murderers, over half reported homosexual experiences. In addition, Beauregard and Proulx (2007) found that in a minority of SHOs specifically targeting males, a group of “sexual predators” was identified, very similar to the sadistic offender or the lust murderer described by Geberth (1996). However, the connection between the presence of sadism and targeting male victims will require further research.
Although several studies have suggested that sadistic offenders were more skilled at avoiding detection (e.g., Dietz et al., 1990), to our knowledge no studies actually tested specifically for this. The current study is a pioneer effort to uncover the relationship between sadism and forensic awareness. Two different measures were used to examine avoiding detection: whether or not the case remained unsolved and the number of days before body recovery. Although the case status is obvious, the use of the number of days before body recovery was used as it has been shown that the longer it takes to recover the victim’s body, the less chance to recover forensic evidence to analyze, and subsequently identify the offender. Moreover, Beauregard and Martineau (2014) have shown that the two measures were positively correlated. Interestingly, our findings showed a different pattern. Sadistic SHOs were more likely to remain undetected compared with nonsadists but at the same time, the police was more likely to recover the victim’s body earlier . This is similar to what Beauregard and Martineau (2016) have found in their sample of SHOs. The authors examined behaviors of the organized SHO as defined by Ressler et al. (1988). What they found was that although selecting less risky locations was positively associated to both avoiding and delaying detection, they found that behaviors such as moving the victim’s body had the opposite effect on avoiding and delaying detection. Moreover, we believe it is plausible that with a sadistic offender, part of his experience and enjoyment may be to leave the victim where they may be found in a state that is shocking. While this cannot be tested in our article, it is hypothesized that the finding of the victim’s body discovered sooner may be in line with the offender’s desire. Overall, this study supports the notion that sadistic offenders are more “rational” offenders who pose a greater risk for evading police detection based on conscious efforts to impede police investigations. This is especially concerning for police, as this population is generally believed to be at a considerable risk for recidivism (Berner, Berger, & Hill, 2003) and thus creates a serious threat to public safety.
Conclusion
The current study provides insight into how investigative awareness in sexual homicide cases can be identified as a distinctive feature of sexual sadism. More specifically, it adds to current research that highlights the importance of behavioral differences between SHOs. The findings in the present study also support the notion that sadistic fantasies can underlie the motivation behind a sexual homicide and lead the offender to more successfully evade police detection through better preparation, planning of the crime, and taking care of possible forensic evidence that could be left at the crime scene. As suggested in previous studies, sadistic SHOs present a greater investigative awareness than nonsadists, which actually lead them to avoid police detection. The current findings have important implications for the understanding of sadism as well as the identification of sadistic offenders by both clinicians and the police. The study shows that not all SHOs present investigative awareness and that not all of them are capable of avoiding police detection. However, the study also shows that the SHOs who display behaviors related to investigative awareness are more likely to be sadists. We believe this constitutes another objective feature easier to use than the diagnostic criteria of the DSM or the ICD-10 to identify sadistic offenders.
The current study is not without limitations. The sample only includes sexual homicide cases from Canada, which may not be representative of all cases of sexual homicide. The use of police data is limited to what is observed by police at the crime scene or revealed through the investigation (Beauregard & Martineau, 2014). Also, as some of the case statuses are unsolved, it is not possible to examine offender characteristics. Thus, we can only hypothesize that offenders whose case status remained unsolved were the result of having the intention to avoid detection and made choices to obtain this particular outcome (Beauregard & Martineau, 2014). Clinical studies are therefore needed to offer a more detailed picture than what is provided by solely using police data. Moreover, we cannot conclude how these offenders gained their investigative awareness. It is possible that a number of different factors could account for this, including prior experience with the criminal justice system or learnt behaviors from previous offenses for which the offender was not caught. An important focus for future studies would therefore be to examine the role of other factors that may lead to an offender becoming more forensically aware. In addition, no legal definition of sexual homicide exists which means that identification is entirely up to police investigators, making it possible that some sexual homicides go unnoticed because the offender removed forensic evidence or the body was never found (Beauregard & Martineau, 2014). Future research would benefit from including offender characteristics and contextual aspects of the crime. In addition, it would be ideal to compare results with clinical studies that have access to sexual fantasies to confirm consistency in the results of the current study and increase generalizability. Moreover, it would be important to replicate the study with a sample from different countries, especially from non-Western countries to see if the findings are similar and if the concept of investigative awareness is culturally dependent. Further research on the utility of SAD-SEX-SH-R in accurately predicting sadism would be beneficial to determine reliability and reproducibility within sexual homicide.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
