A Descriptive Study of Sexual Homicide in Canada

Abstract

Few empirical studies have been conducted that examine the phenomenon of sexual homicide, and among these studies, many have been limited by small sample size. Although interesting and informative, these studies may not be representative of the greater phenomenon of sexual murder and may be subject to sampling bias that could have significant effects on results. The current study aims to provide a descriptive analysis of the largest sample of sexual homicide cases across Canada in the past 62 years. In doing so, the study aims to examine offender and victim characteristics, victim targeting and access, and modus operandi. Findings show that cases of sexual homicide and sexual murderers included in the current study differ in many aspects from the portrait of the sexual murderer and his or her crime depicted in previous studies. The authors’ results may prove useful to the police officers responsible for the investigation of these crimes.

Keywords

sexual homicide sexual murderer police investigation modus operandi

Introduction

Several books, many anecdotal, and studies have been dedicated to studying a highly select group of convicted homicide offenders, namely, sexual murderers. However, few empirical studies have been conducted that examine the phenomenon of sexual homicide and its evolution over the last 62 years. Since the publication of the seminal work on sexual homicide by members of the FBI (Burgess, Hartman, Ressler, Douglas, & McCormack, 1986; Ressler, Burgess, Douglas, Hartman, & D’Agostino, 1986; Ressler, Burgess, Hartman, Douglas, & McCormack, 1986), less than 40 studies on the topic have been published (Chan & Heide, 2009). Among these empirical studies, many have been limited by small sample size (Chan & Heide, 2008). For instance, typologies of sexual murderers have been identified based on samples with less than 50 offenders (e.g., Beauregard & Proulx, 2002; Ressler, Burgess, Douglas, et al., 1986). Although interesting and informative, these studies may not be representative of the greater phenomenon of sexual murder and may be subject to sampling bias that could have significant effects on results. Sexual murderers who agreed to participate in these studies may differ in important ways from those who refused. As a consequence, the portrait of the sexual murderer and his offense may be only partial or worse, biased by an overrepresentation of certain types of offenders.

The problem of small sample size among studies on sexual homicide emanates, at least in part, from the rare occurrence of this type of homicide. Studies have identified low base rates for sexual homicide, estimating that they represent between 1% and 4% of all homicides in North America (Chan, Heide, & Myers, 2012; Meloy, 2000; Roberts & Grossman, 1993). The rarity of these homicides has not only contributed to the lack of empirically sound knowledge on sexual homicide but also leads to difficulties apprehending and prosecuting these offenders. Detectives working on these cases cannot necessarily rely on their experience of previous investigations. Moreover, sexual homicide cases can be difficult to solve, particularly when they involve a stranger victim (Proulx, Beauregard, Cusson, & Nicole, 2007). Because of the complexity of sexual homicide cases, such investigations are not immune to criminal investigative failures (Rossmo, 2009).

Although sexual homicides may differ in offender motivation, sexual behavior, and level of violence, it is possible to identify common characteristics across cases. Previous studies have provided some insight in relation to these characteristics and will be discussed in the following sections. The current study aims to provide a descriptive analysis of the largest sample of sexual homicide cases across Canada in the last 62 years. In doing so, the study aims to examine offender and victim characteristics, victim targeting and access, and modus operandi (MO). This information may prove useful to the police officers responsible for the investigation of these crimes.

Offender and Victim Characteristics

In their meta-analytical review of the characteristics of nonserial sexual murderers, Carter and Hollin (2010) found that the mean age of offenders within the included studies ranged from 22 to 38 years. Although there was large variance among the studies, the mean age across all studies was 24 years. With respect to marital status of offenders, most studies indicate that sexual murderers were not in a relationship at the time of the offense (Beech, Fisher, & Ward, 2005; Briken, Habermann, Berner, & Hill, 2005; Langevin, Ben-Aron, Wright, Marchese, & Handy, 1988; Nicole & Proulx, 2007). Interestingly, most sexual murderers were found to be White (Chan, Myers, & Heide, 2010; Grubin, 1994; Milsom, Beech, & Webster, 2003; Proulx et al., 2007; Swigert, Farrell, & Yoels, 1976; Warren, Hazelwood, & Dietz, 1996), regardless of where the study took place.

Some sexual murderers engage in paraphilic behaviors. Grubin (1994) reported the presence of paraphilic behavior in almost half of the sexual murderers in his sample, whereas Langevin et al. (1988) as well as Briken et al. (2005) found evidence of sexual sadism in many of the cases of sexual homicide studied. Finally, most sexual murderers have a criminal history. The majority of sexual murderers in Nicole and Proulx’s (2007) study had a criminal record, including previous sex offense convictions. Moreover, about one third of sexual murderers in the studies by Oliver, Beech, Fisher, and Beckett (2007) and Grubin (1994) had a previous conviction for rape and about half of the offenders in both studies had prior convictions for violent offenses.

The majority of sexual homicide victims are female strangers or casual acquaintances of the offender (Meloy, 2000; Roberts & Grossman, 1993), although a minority of sexual murderers specifically target males (Beauregard & Proulx, 2007). The victims are also mostly White (Chan et al., 2010) as sexual homicide is a form of crime typically committed intraracially (although Chan et al., 2010, found that Black sexual murderers killed also interracially). However, in their studies on sexual murderers of elderly victims, Safarik and his colleagues showed that when Black sexual murderers were involved, the crimes were more likely to be interracial, with White victims being the most likely targets (Safarik, Jarvis, & Nussbaum, 2000, 2002). Whereas most victims of sexual homicide are adults, some sexual murderers specifically target child victims (Beauregard, Stone, Proulx, & Michaud, 2008). In their study of sexual homicide in Canada, Roberts and Grossman (1993) found that 12% of victims were between 1 and 10 years of age and 37% were between 11 and 20 years of age. Finally, prostitutes are specifically targeted by some sexual murderers. A study by Brewer et al. (2006) showed that involvement in prostitution considerably increases a woman’s risk of becoming a victim of homicide. Although not all prostitute homicides are sex related (e.g., dispute over appropriate amount of money paid for the sexual service, hate crime), in most cases, the context of the crime and the crime scene (e.g., victim found naked) suggests a sexual component to the murder. The same study estimated that serial killers accounted for 35% of prostitute homicides.

Victim Targeting and Access

According to Carter and Hollin (2010), the majority of sexual homicide research fails to address the issue of victim access. Although the majority of studies do not address how the offender gained access to their victims, a few studies have examined where they do so. Roberts and Grossman (1993) report that most sexual homicides take place in the victim’s residence or in a public location. Similarly, Langevin et al. (1988) found that sexual homicides take place in the victim’s residence in more than one third of cases, whereas Grubin (1994) found that access was gained through breaking and entering into the victim’s residence or by stalking the victim on the street.

MO

Many studies have found strangulation to be the most common method of inflicting death in cases of sexual homicide (Carter & Hollin, 2010). Other methods commonly used include stabbing and beating (Roberts & Grossman, 1993). Firearms are rarely used by sexual murderers (Grubin, 1994; Roberts & Grossman, 1993). Compared with nonsexual homicide, sexual murderers are more likely to use personal and close contact weapons than firearms (Chan & Heide, 2008). In their study of 36 nonserial sexual murderers, Beauregard and Proulx (2002) found that about a quarter used restraints and mutilated the victim’s body, and less than 10% dismembered the victim following the homicide. Similarly, in a study by the FBI, it was found that in approximately 40% of cases, the offenders used restraints and that in 27% of cases, the offender took something from the scene or kept a souvenir (Ressler, Burgess, & Douglas, 1988). Moreover, they found that in about a third of the cases, the offender mutilated and had sex with the victim postmortem (Ressler, Burgess, Douglas, et al., 1986). A study conducted on a nonrandom sample of 211 sexual homicide cases from the FBI Behavioral Analysis Unit found a lower incidence of necrophilia, with evidence of postmortem sex in 16 cases (7.6%). The authors of this study suggested that the most common explanation for this behavior is the desire to have an unresisting partner; however, this explanation may not be applicable in all cases of sexual homicide (Stein, Schlesinger, & Pinizzotto, 2010).

Some offenders will adapt their MO or take precautions before, during, or post crime commission to decrease their risk of apprehension. Arguably, this adaptation of crime strategy may be deemed an indication of evolving criminal sophistication on the part of the offender. Offenders who adapt their MO to thwart police investigative efforts may be said to be exhibiting investigative awareness (i.e., a knowledge or understanding of police investigative practice). A related concept coined in criminological research as forensic awareness (Davies, 1992) refers to an offender’s knowledge or understanding of the importance of forensic evidence (e.g., DNA, fingerprints, dental impressions) to police investigation.

There is a dearth of research on the extent of forensic awareness among offenders and the impact that this awareness has on the crime process and investigation. A small number of studies, specific to sexual crime, have addressed the issue of forensic awareness and provide some insight into how certain offender behaviors may be indicative of forensic and/or investigative awareness. Davies and Dale (1995) studied stranger rapists and suggested that travelling longer distances to commit an offense may be indicative of forensic awareness. Beauregard and Field (2008) identified a precaution (i.e., moving a victim’s body post murder) that may be undertaken to delay apprehension but may also be considered an indicator of investigative and forensic awareness. Moving the body complicates the investigation by decontextualizing the crime, potentially decreasing the likelihood that the victim will be found or if found, identified. This action may also indicate forensic awareness as the offender is removing a significant source of forensic evidence from the scene of the homicide. In their examination of 222 stranger sexual assaults, Beauregard and Bouchard (2010) found that certain target selection behaviors (i.e., nonrandom selection of a victim, selecting a victim who is alone, and hunting for a victim in certain locations, such as a prostitution stroll), arguably indicators of investigative awareness, were related to forensic awareness, which was evident at the crime scene. Furthermore, offenders who break and enter the homes of their victim and exhibit certain sexual behaviors (i.e., penetrate the victim and ejaculate) are more likely to exhibit forensic awareness. A negative relationship was found between forensic awareness and the use of drugs and/or alcohol prior to commission of the offense (Beauregard & Bouchard, 2010).

The Current Study

Almost three decades of research have provided us with a portrait of the typical sexual murderer. However, due to the small sample sizes of many of these studies, the portrait may not be representative. The current study aims to enhance our knowledge by providing a more complete picture of the sexual homicide phenomenon over the past 62 years in Canada. Using police data, the current study presents a detailed account of the offenders, the victims, and situational and behavioral characteristics of Canadian sexual homicides to help inform police investigative practice.

Method

Sample and Procedure

To be included in the current sample, all homicide cases had to be identified as completed real incidents (no attempts), and had to involve a sexual element (i.e., there was evidence of sexual activity and/or the crime was sexually motivated). More specifically, the case had to meet the definition of sexual homicide provided by the FBI; that is, 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). Information on all cases of sexual homicide was collected from a national database operated by the Royal Canadian Mounted Police (RCMP). Detectives assigned to the case are required to collect the information from the case file via close-ended and multiple-choice questions approximately 45 days into the investigation. This not only ensures that investigators consider aspects of the crime that may not have otherwise been reported but also forces them to make a choice about particular details of the crime. Data are collected that relate to the victim(s), the potential or suspected offender, the behavior of the offender during and after the crime, and any forensic information that may be available.

A query of the database yielded 600 potential sexual homicide cases investigated by the RCMP. Following a review of these cases by the authors, the sample was reduced to 393 cases with 55 cases needing further confirmation of the sexual component. A second review of all cases resulted in a further reduction of 43 cases, which lacked sufficient evidence of a sexual nature. The final sample includes 350 cases of sexual homicide that occurred between 1948 and 2010. The majority of these cases have been solved (n = 250); however, 100 cases were unsolved at the time they were entered in the database.

Results

Offender Characteristics and Routine Activities Prior to the Sexual Homicide

Table 1 presents the offender characteristics as well as their routine activities prior to the sexual homicide.¹ The average age of sexual murderers is 28 years (SD = 9.88, range = 14-72). The majority of sexual murderers are White (66%); however, a significant proportion is aboriginal² (28.8%). Most sexual murderers do not have a large build; 80% of them are either thin or of average build. The majority are either single (57.2%) or separated/divorced (15.2%). Interestingly, 21.2% of sexual murderers were known (by police) to possess a sexual collection and 23.6% have presented evidence of paraphilic behavior. These offenders also have a diverse criminal history, with an average of 1.7 convictions for violent offenses (SD = 2.6), 0.4 convictions for sexual crimes (SD = 1.0), and 7.3 convictions for property offenses (SD = 13.6). Offenders are described across a number of nonmutually exclusive lifestyle items. Among the current sample, approximately a third frequently engage in social activities (32.4%), a third engage in criminal activities (38%), and only a small number are described as loners, who avoid social contact with other people (11.2%). Few were described as having no fixed address (i.e., homeless; 8%).

Table 1.

Offender Characteristics and Routine Activities Prior to the Sexual Homicide.

Variables	Percentage	Frequency (n = 250)
Offender characteristics
Age of offender	28.4^a	9.00^b
Race of offender
Black	0.4	1
White	66.0	165
Aboriginal	28.8	72
Asian	0.4	1
Other	4.4	11
Physical build
Small (thin)	21.6	54
Medium (average)	58.4	146
Large (stocky)	18.4	46
Obese	1.6	4
Marital status
Single	57.2	143
Married/common law	27.6	69
Separated/divorced	15.2	38
Offender has a sexual collection	21.2	53
Evidence of paraphilic behavior	23.6	59
Prior convictions
Violent (including sexual)	1.7^a	2.6^b
Sexual	0.4^a	1.0^b
Property	7.3^a	13.6^b
Total	13.0^a	19.0^b
Routine activities
Frequently engages in social activities	32.4	81
Avoids social contact with other people	11.2	28
Has no fixed address	8.0	20
Frequently engages in criminal activities	38.0	95

Represents the mean.

Represents the standard deviation.

Victim Characteristics and Routine Activities Prior to the Sexual Homicide

Table 2 presents victim characteristics as well as their routine activities prior to the sexual homicide. There is only a 1-year age difference between the average age of offenders (28) and victims who had a mean age of 27 (SD = 15.51, range = 2-95). The majority of victims are female (89.7%) and White (62.8%), although a significant proportion are aboriginal (33.1%). More than a third of the victims abuse alcohol (38%) and one out of four abuses drugs (25.7%). A third of the victims like to socialize or party (32%), whereas only a minority are described as loners (2.9%) or homeless (11.1%). It is noteworthy that 17.7% of the victims were known to engage in prostitution. As illustrated in Table 2, victims were engaged in various activities prior to their murder, the most frequent being domestic activities (i.e., activities relating to the home or family, 20.3%). This is followed by 17.1% of victims engaged in jogging/walking, 11.4% in partying, 9.7% each hitchhiking or socializing at a bar, and 8.3% were working as prostitutes.

Table 2.

Victim Characteristics and Routine Activities Prior to the Sexual Homicide.

Variables	Percentage	Frequency (n = 350)
Victim characteristics
Age of victim	27.2^a	15.0^b
Victim is female	89.7	314
Race of victim
Black	0.9	3
White	62.8	220
Aboriginal	33.1	116
Asian	2.0	7
Other	1.2	4
Victim abuses alcohol	38.0	133
Victim abuses drugs	25.7	90
Victim likes to socialize/ party^c	32.0	112
Victim is a loner	2.9	10
Victim is homeless	11.1	39
Victim is a prostitute	17.7	62
Routine activities
Domestic activities	20.3	71
Sleeping	7.1	25
Babysitting	0.3	1
Playing	2.6	9
Dining	1.1	4
Shopping	0.9	3
Travelling to or from somewhere	8.6	30
Driving or riding in a vehicle	5.4	19
Being in a parking lot	1.7	6
Jogging/walking	17.1	60
Hitchhiking	9.7	34
Sports or recreational activities	5.5	19
Socializing in a bar	9.7	34
Visiting friends/relatives	6.3	22
On a date	1.4	5
Partying	11.4	40
Working	2.6	9
Working as a prostitute	8.3	29

Represents the mean.

Represents the standard deviation.

Participates in social situations and attends events where other people (including acquaintances and strangers) gather.

Characteristics of the Contact, Offense, and Body Recovery Scenes

Sexual murderers most frequently encountered their victims in outdoor locations (30%) or at the victim’s residence (21.4%). Similarly, the offense scene is most often in an outdoor location (36.3%) or at the victim’s residence (21.4%). As with the encounter and offense scenes, approximately 20% of victims’ bodies were recovered within their own residence. The vast majority of sexual murderers, however, disposed of their victims’ bodies in an outdoor location (61.4%). Table 3 shows the various initial contact, offense, and body disposal locations.

Table 3.

Characteristics of the Contact, Offense, and Body Recovery Scenes.

Variables	Percentage	Frequency (n = 350)
Contact scene
Victim’s residence	21.4	75
Business location	12.9	45
Transportation related location	12.9	45
Entertainment location	12.9	45
Public building	3.1	11
Outdoors	30.0	105
Parking location	3.1	11
Water location	1.4	5
Offense scene
Victim’s residence	21.4	75
Business location	6.6	23
Transportation related location	7.1	25
Entertainment location	0.9	3
Public building	3.7	13
Outdoors	36.3	127
Parking location	2.3	8
Water location	3.4	12
Body recovery scene
Victim’s residence	20.3	71
Business location	4.9	17
Transportation related location	5.4	19
Entertainment location	0.9	3
Public building	4.0	14
Outdoors	61.4	215
Parking location	1.4	5
Water location	10.9	38

Although not shown in the table, slightly more than half (54.5%) of sexual homicides involved more than one crime scene (i.e., a separate initial contact, offense, and body disposal location). Only 10.9% of sexual homicides involve three separate crime locations and 43.6% involve two crime locations. The remaining 45.5% of sexual murderers encountered, killed, and disposed of their victims in a single location.

MO and Unusual Acts Observed at the Crime Scene

Table 4 presents the MO and the unusual acts that were observed at the crime scene of the sexual homicide. Only a minority of sexual murderers targeted a specific victim (18.9%), whereas the majority appeared to select their victims at random. Most sexual murderers used a con (e.g., befriended the victim, requested the victim’s assistance, feigned an emergency) to approach their victim (40.6%). Only a minority of sexual murderers surprised (7.1%) their victims (e.g., attacked victim while victim was sleeping) or blitzed (12.3%) their victims (e.g., immediately overpowered their victims through violence). The violence suffered by victims of sexual homicide is diverse. Sexual murderers most frequently beat (47.1%) or strangled (41.7%) their victims. Approximately 22% of victims were stabbed. Offenders cut and/or asphyxiated their victims in 12.9% of cases each.³ Forms of violence that occurred less frequently were stomping (5.4%), shooting with firearm (4.6%), crushing (4.3%), drowning (4.1%), and burning (3.4%).

Table 4.

Modus Operandi and Unusual Acts Observed at the Crime Scene.

Variables	Percentage	Frequency (n = 350)
Modus operandi
Offender targeted the victim	18.9	66
Type of approach
Con	40.6	142
Surprise	7.1	25
Blitz	12.3	43
Type of violence
Beating	47.1	165
Stabbing	22.3	78
Cutting	12.9	45
Stomping	5.4	19
Crushing	4.3	15
Burning	3.4	12
Strangulation	41.7	146
Asphyxiation	12.9	45
Drowning	4.0	14
Gunshot	4.6	16
Any use of restraints	10.9	38
Restraints removed by offender	2.3	8
Any use of blindfolds or gags	7.1	25
Any use of weapon	60.6	212
Weapon recovered^a
Not recovered	43.0	80
At the scene	40.3	75
Elsewhere	16.7	31
How offender obtained weapon^a
Brought to the scene	51.9	81
Found at the scene	43.6	68
Taken from victim	4.5	7
Type of weapon used^a
Knife	37.1	73
Firearm	7.6	15
Axe/hatchet	3.6	7
Bludgeoning	25.4	50
Ligature	20.3	40
Other	6.1	12
Unusual acts
Foreign objects inserted into the victim	11.4	40
Mutilation of genitalia	5.4	19
Any bizarre acts	5.7	20
Offender bite the victim	7.4	26
Overkill	43.1	151
Offender took any items from victim/offense	37.7	132
Post-mortem sexual activity	10.6	37
Dismemberment of the body	6.3	22

Information for this variable was available for 185 offenders.

The offender used a weapon in 60.6% of cases. With respect to weapon origin, the offenders either brought the weapon to the scene (51.9%) or found it at the scene (43.6%). The most common type of weapon was a knife (37.1%), followed by a bludgeoning instrument (25.4%) and a ligature (20.3%). A firearm was the weapon of choice in only a few cases. The offender used more than one weapon in 65 cases (18.6%). In 47 of these cases (69.1%), the offender used more than one weapon type (e.g., knife and ligature were used). In the majority of cases, weapons were recovered; however, police were unable to recover weapons in 43% of cases.

Only a few sexual murderers used restraints (10.9%) or blindfolds (7.1%) on the victim. As to the unusual acts observed at the crime scene, it is noteworthy that in 43.1% of the cases, evidence of overkill (i.e., the investigating officers believed that offender used more force than was necessary to kill the victim) was noticed and that items were taken from the victim in 37.7% of the cases. Only a few sexual murderers mutilated the genitalia of the victim (5.4%), bit (7.4%), or dismembered the victim’s body (6.3%). Evidence of postmortem sexual activity was observed in 10.6% of cases.

Types of Sexual Acts Committed During the Crime

Table 5 presents the different types of sexual acts committed during the crime. In almost half of the cases (46.3%), vaginal penetration was observed. This is the most typical sexual act committed during sexual homicide. Some offenders committed anal penetration (16.3%), fellatio (8.6%), fondling (9.1%), or penetrated the victim with an inanimate object (8.0%). Less common forms of sexual activity, such as ejaculating on the victim, vaginal or anal fisting, and urinating or defecating on the victim were observed in less than 1% of the cases.

Table 5.

Types of Sexual Acts Committed During the Crime.

Variables	Percentage	Frequency (n = 350)
Vaginal intercourse	46.3	162
Anal intercourse	16.3	57
Fellatio	8.6	30
Cunnilingus	0.9	3
Penetration with fingers	3.1	11
Masturbation	1.7	6
Fondling	9.1	32
Sucking breasts	0.9	3
Ejaculation on victim	0.6	2
Inanimate object penetration	8.0	28
Vaginal fisting	0.9	3
Anal fisting	0.3	1
Urinating on victim	0.3	1
Defecating on victim	0.3	1

Characteristics of Forensic Awareness Strategies Exhibited by the Offender

Finally, Table 6 presents the different precautions, including forensic awareness strategies utilized or exhibited by offenders during the commission of the sexual homicides. An offender who takes additional steps and adapts their MO to specifically hide evidence to ultimately avoid apprehension is potentially exhibiting forensic awareness (Davies, 1992). In more than half of the sexual murders, police could not identify the use of any forensic awareness strategies during the commission of the crime. However, 24.9% of offenders were found to use one strategy, 11.7% used two strategies, and a small group of offenders (9.1%) used three or more strategies during their crime. The most common strategy used was to destroy/remove evidence (30.6%); this includes wearing gloves, using a condom, setting fire to the scene, and cleaning the scene. This is followed by acting on the victim and/or the environment (11.4%). Such precautions include threatening the victim not to report, disabling the lighting, the telephones, security system, and/or the victim’s vehicle, administrating a drug to the victim, tying up the victim, blocking access in and out of doors or windows, and killing the victim for the purpose of eliminating the witness. Other offenders simply disposed of the body (11.1%), whereas a minority attempted to protect their identity (4.3%) through the wearing of a mask, giving out a false name, attempting to disguise or altering their appearance, and changing residence after the crime. Some offenders used “other” precautions (10.3%), which included using a scanner to ascertain police activities, using a devise to alert them to anyone approaching, using a lookout or establishing a lookout location where the offender could observe the scene without being noticed, covering the victim’s eyes, gagging the victim, and arranging an alibi. Staging of the crime scene was observed in only 0.9% of the cases. Interestingly, semen was found at the scene in slightly more than a quarter of the cases, presenting the possibility for DNA analysis. It is uncertain whether a lack of DNA evidence at the crime scene is the result of a conscious effort on the part of the offender to ensure no forensic evidence is left behind or is simply the result of the murderer experiencing a sexual dysfunction during the crime (Ressler, Burgess, Douglas et al., 1986). However, the absence of DNA, at least in some cases, could be indicative of a level of forensic awareness on the part of the offender.

Table 6.

Characteristics of Forensic Awareness Strategies Exhibited by the Offender.

Variables	Percentage	Frequency (n = 350)
Precaution used by offender
Destroying or removing evidence	30.6	107
Protecting his identity	4.3	15
Acting on victim and/or the environment	11.4	40
Staging the crime scene	0.9	3
Disposing of victim’s body	11.1	39
Other precaution	12.0	42
Number of forensic awareness strategies used
0	54.3	190
1	24.9	87
2	11.7	41
3 or more	9.1	32
Any semen located	27.7	97
Body moved	34.0	119
Number of days before recovery	71.1^a	384.2^b
Risk of being detected—Contact scene (0-2)	0.9^a	0.9^b
Risk of being detected—Offense scene (0-2)	0.5^a	0.8^b
Risk of being detected—Body recovery scene (0-2)	0.5^a	0.8^b

Represents the mean.

Represents the standard deviation.

The offender moved the victim’s body from the offense scene to a body disposal site in 34% of the cases. On average, it took 71 days from the time of the offense until the discovery of the victim’s body (SD = 384.2, range = 64-91). To examine the level of risk taken by the sexual murderers while committing their crimes, risk scales were created for the contact, the offense, and the body recovery scenes. These scales were computed by summing two dichotomous (0 = no, 1 = yes) items together—(a) potential to see what was happening and (b) potential to hear what was happening—for each scene of the crime. The reliability analyses showed strong consistency within the scales, Cronbach’s alpha reaching .90, .89, and .87 for contact, offense, and body recovery scenes, respectively. As illustrated in Table 6, although the risks taken by sexual murderers is on average close to 1 (scale ranging from 0 to 2) at the contact scene (SD = 0.9), the risk drops to 0.5 on average at the offense and body recovery scenes.

Discussion

Previous studies on sexual homicide have begun to create a portrait of the sexual murderer and his offense. Although these studies have been used to inform police practice and offender/offense profiling, the majority suffer from small samples which may not be representative of all sexual murderers. Moreover, to assist police and inform investigative practice, studies must provide an in-depth examination of the behaviors exhibited by sexual murderers in the commission of their crimes. The contribution of the current study is shedding more light on this rare form of violence and providing a more complete picture of the offenders, victims, and methods by which offenders commit their offenses. This information may be of some use during police investigations.

Offender and Victim Characteristics

The offenders included in the current study tend to be older on average than the sexual murderers included in previous studies. The average age of offenders in studies cited by Carter and Hollin (2010) is 24 years, compared with 28 years in our study. The observed age difference may be a result of our larger sample. When examined in combination with criminal history data, this age difference takes on a totally different meaning for the investigation of sexual homicide. Sexual murderers typically have a criminal history or have established a criminal career. In two studies, up to one third of the offenders had a prior conviction for rape (Grubin, 1994; Oliver et al., 2007). Sexual murderers in our sample have an average of 0.4 prior convictions for sexual crimes, with approximately 80% of the offenders having no prior sexual convictions. The investigative strategy of prioritizing “known sex offenders” would thus likely be unproductive as the majority of sexual murderers have no prior convictions for sexual crimes.

As to the race of the offender, our findings are in line with previous studies that have shown that sexual murderers are more likely to be White (e.g., Chan et al., 2010; Grubin, 1994; Proulx et al., 2007). However, our findings show that more than one in every four offenders are aboriginal. This group appears to be overrepresented in this type of crime. No other studies to date have found similar results, even those conducted in Canada where larger populations of aboriginal peoples may be found.

Our findings replicate those of other studies regarding the marital status of sexual murderers. Almost three quarters of the offenders in our sample were single or separated/divorced. This finding, however, should not be interpreted as sexual murderers having a tendency for social isolation as suggested by Grubin (1994). In fact, our findings show that one third of the offenders frequently engaged in social activities and that only 11.2% were described as avoiding social contact with other people. This is important to consider when profiling such cases or attempting to prioritize suspects.

Paraphilic behaviors appeared to be less prevalent among the sexual murderers in our study, in comparison with those in Langevin et al. (1988). One possible explanation for this finding is the difference between police and clinical data. Having access to the offender during an assessment or treatment allows the opportunity to question him on multiple aspects of his sexual history, whereas the police have less time to devote to this component, their mandate being very different. Therefore, the lack of paraphilic behaviors among the present sample may be attributed more to the data source than to the actual absence of such behavior. The current study did, however, examine whether the offender was known to maintain a sexual collection (e.g., pornography, sexual paraphernalia). The act of collecting erotica or other sexual materials may be related to paraphilic behavior (Seto, Cantor, & Blanchard, 2006). Depending on the nature of the materials, they may in fact serve to stimulate or encourage specific paraphilia. One out of every five sexual murderers in our sample was known by police to possess a sexual collection. This information may be useful during police investigations, especially when preparing an affidavit in support of a collateral material search warrant (Hazelwood & Warren, 1995).

Investigators consider various aspects of victimology when investigating sexual homicides. Sexual murderers tend to select victims within their own age group. The average age of victims mirrors the average age of offender in our sample. However, some sexual murderers specifically target child victims. In fact, almost 30% of the victims in our sample were less than 18 years of age. Most studies on sexual murderers have focused on adult victims or have failed to differentiate between adult and youth victims. Yet, some studies have suggested important differences between those who target adult victims and those who target children. For instance, Beauregard et al. (2008) found that sexual murderers who target children more often use pornography and have contact with the victim prior to crime, and their offenses more often involve premeditation, strangulation, and hiding and dismemberment of the body than do sexual murders of adult women. As a group, sexual murderers of children exhibit some unique attributes, but they also share several characteristics with adult sadistic offenders (Beauregard et al., 2008).

Although most studies report that victims of sexual homicide are female, in the current study, slightly more than 10% of the victims are male. The sexual orientation of the sexual murderer may be a simple explanation for their target selection, such that homosexual murderers will target males due to sexual preference. However, sexual murderers targeting males do not always present a homosexual orientation (Beauregard & Proulx, 2007).

A proportion of the victims in the current study may be considered vulnerable due to lifestyle. That is, their lifestyle may have contributed to their victimization by making them an easier target for the offender. About a third of the victims abuse alcohol or like to party and one in every four victims abuse drugs. These constitute “vulnerability” factors that may be identified by the offenders prior to selecting their target. Another vulnerability factor significantly present in sexual homicide is prostitution. Almost one in five victims was a prostitute in our sample. This might not come as a surprise as Brewer et al. (2006) noted prostitutes have the highest homicide victimization rate among women. Because of the nature of their work, these women find themselves in high-risk situations (e.g., cheap motel/hotel room, in the offender’s vehicle), where supervision or the chance of somebody interfering with the criminal plan is very unlikely. However, some offenders specifically target these victims as in addition to their situational vulnerability, prostitutes exhibit additional characteristics and behaviors that result in increased risk for victimization. In general, prostitutes are known to be highly mobile and less likely to inform their family or friends when moving to a different city or state/province. This has direct consequences for the criminal investigation, as their disappearance is less likely to be immediately noticed and reported to the police (Levi-Minzi & Shields, 2007). This was illustrated with the recent case of Robert Pickton in British Columbia who has been convicted of killing six prostitutes—and suspected of having killed 43 more—from the Downtown East Side, a neighborhood of Vancouver, Canada.

Victim Targeting and Access

As found in previous studies, the majority of sexual murderers are killing their victims in the victim’s residence or at an outdoor location (Grubin, 1994; Langevin et al., 1988; Roberts & Grossman, 1993). In the current study, these two locations account for more than 50% of all attack sites. The inclusion of information on the encounter and body disposal sites in the current study allows for an examination of crime scene patterns. Although the overall pattern between the contact and the offense scenes seems to exhibit stability (i.e., approximately 20% victim residence and approximately 30% outdoor location for both scene types), clearly the majority of sexual murderers decide to switch location for the purpose of disposing of the body (Leclerc, Wortley, & Smallbone, 2010). Hence, although the choice of an outdoor location is around 30% for the contact and offense scenes, it doubles for the body recovery scene.

The commonly held belief that women are safe in their homes and at greater risk when outside of the home is not supported by the current findings. According to Warr (1988), the victim’s residence should be regarded as a major locus of sexual crimes. Sexual crimes where the offender gains access to victims through the use of a home-intrusion technique (Warr, 1988, see also Beauregard, Proulx, Rossmo, Leclerc, & Allaire, 2007)—that is, breaking and entering—resemble a hybrid offense, that is, a violent crime with the opportunity structure of a property crime. Hence, the same characteristics that make a dwelling attractive to a burglar (e.g., easy access, easy escape, clear view inside the home) are also likely to make it attractive to sex offenders. This carries practical implications for the investigation of sexual homicide cases; as Schlesinger and Revitch (1999) found, there is a 77% chance that the offender has a history of sexual burglary when the victim is killed in her residence (see also Davies, Wittebrood, & Jackson, 1997). This information could be used in the prioritization of suspects by the police.

MO

As found in previous studies on sexual homicide, the most common cause of death in the current study was strangulation/asphyxiation (Carter & Hollin, 2010). However, our study showed that even if strangulation is the method of choice to kill the victim, more than half of the sexual murderers used a weapon during the commission of the crime. Compared with nonsexual homicide, firearms are rarely used in sexual homicide. Although some sexual murderers may use a weapon to control the victim during the crime or to mutilate their victim, in most cases, the weapon is not used to inflict fatal wounds. This was evidenced in our study with a knife being the most common weapon used. Contrary to the sensationalized portrayal of the sexual murderer blitzing an unsuspecting victim, many sexual murderers utilize a con to make contact with their victims. In our sample, two out of every five offenders used a con⁴ or a ruse to approach their victim. This finding is important for the investigation of these cases as it suggests that in almost half of the cases, sexual murderers possess the necessary social skills to approach their victims under false pretense. This once again contradicts the image of the introverted socially inapt offender as depicted in previous studies (e.g., Grubin, 1994).

Previous studies have indicated that sexual murderers may engage in unusual or bizarre behaviors toward their victim or at the crime scene (e.g., Ressler, Burgess, Douglas, et al., 1986; Ressler, Burgess, Hartman, et al., 1986; Ressler et al., 1988). Unusual acts were present among the current sample, however, were very infrequent. For instance, genitalia mutilation, biting, dismemberment, and necrophilia occur in less than 11% of cases. Although these behaviors may prove useful in profiling and in case linkage (see Stein et al., 2010, for necrophilia, and Häkkänen-Nyholm, Weizmann-Henelius, Salenius, Lindberg, & Repo-Tiihonen, 2009, for mutilation), they occur too rarely to be used in the identification and construction of sexual murderer typologies (Canter, Alison, Alison, & Wentink, 2004). One behavior, however, that has been reported in previous studies as being unusual and rare appears with greater frequency in our study: overkill. Overkill is defined as inflicting more grievous bodily harm on the victim than is necessary to cause death (Geberth, 1996). Overkill needs to be distinguished from “underkill”—that is, the offender was not effective in his killing method and therefore had to inflict a large number of wounds before finally killing the victim. Overkill was reported by investigators as present in 43% of the cases of sexual homicide included in the current study. Overkill was considered to be present if the victim’s body exhibited more trauma than was necessary to end the victim’s life. For example, overkill would be considered present in a case where an offender fatally stabs the victim and then goes on to slit the victim’s throat. Given the frequency of overkill within the current sample, it may be possible to include this behavior in the development of new offender typologies or validate existing typologies for which overkill helps distinguish types.

Very few studies have examined forensic awareness, which is particularly the case in sexual murderer research. Taking additional steps and adapting the MO used in their crime to specifically hide evidence to ultimately avoid apprehension is not as common as we would have expected. Only one third of the offenders included in our study moved the victim’s body after the murder. Moving the victim’s body after the murder has been linked to an expressive crime scene, indicating an impulsive and personal aggression (Salfati, 2000, 2003; Salfati & Bateman, 2005; Santtila, Canter, Elfgren, & Häkkänen, 2001). Moreover, Beauregard and Field (2008) found that sexual murderers presenting “organized” psychological characteristics are more likely to move the victim’s body after the crime, compared with offenders presenting disorganized characteristics, which is congruent with previous literature in which offenders who are impulsive, unstable, and excessively violent, and who lack organization in their crime scenes, are more apt to leave the body at the crime scene (Beauregard & Proulx, 2002; Ressler, Burgess, Douglas, et al., 1986; Ressler, Burgess, Hartman, et al., 1986; Ressler et al., 1988). The finding is also consistent with the organized offender in Ressler et al.’s (1988) model; according to Ressler et al., organized sexual murderers are in control during the crime, making sure not to leave evidence at the crime scene and transporting the victim’s body to a different location to hide it. Therefore, transporting the victim’s body to a different location may serve the purpose of both obscuring any potential connections between the offender and the body dump site and delaying the discovery of the body. As such, our study is showing that it takes on average 71 days to recover the victim’s body after the murder. However, the standard deviation is very large (SD = 384.2) suggesting great variation. It can be hypothesized that the longer it takes to find the body, the more chance of the forensic evidence being destroyed or lost, and the less probability of solving the crime.

Surprisingly, more than half of the sample used no specific precaution to avoid detection during the crime. This information is useful for the investigators of these crimes as it suggests that offenders were not particularly concerned about the evidence that they may have left behind or were not criminally sophisticated enough to take precautionary measures. However, for those offenders whose actions exhibited concern about forensic evidence, it is noteworthy that most of these offenders used two or more precautions. The most common strategy is the destroying or removing of evidence. Sexual murderers will wear gloves, a condom, or will set fire to or clean the scene following the murder. Although understudied, an understanding of offenders’ forensic awareness may be valuable for the police. Two main hypotheses have been suggested to explain the formation of forensic awareness by offenders. First, the sensationalization and publicity around the collection and use of forensic evidence to apprehend criminals in popular media—the so-called “CSI effect”—may be increasing offenders’ forensic awareness. Second, an offender’s level of forensic awareness may be an indicator of previous encounters with the criminal justice system. Offenders who have experience within the justice system may become educated in evidentiary procedure and, therefore, are aware of the importance of removing evidence from a crime scene (Beauregard & Bouchard, 2010; Davies, 1992). This latter hypothesis seems to find support in two studies in particular. In a study comparing the behaviors of single and serial rapists, it was found that offenders with a more extensive criminal career were more likely to exhibit signs of forensic awareness (Park, Schlesinger, Pinizzotto, & Davis, 2008). Similarly, Davies et al. (1997) in their examination of criminal antecedents of 210 cases of solved stranger sexual assaults found that, in cases of rape, offenders who destroyed DNA evidence, and took fingerprint and sighting precautions, were approximately 2 to 4 times more likely to have prior convictions for sexual offenses. However, if an offender did not take precautions, he was more likely to be a first time sexual offender and may have been under the influence of drugs at the time of the offense. A diminished intellectual capacity likely reduced their capacity for exhibiting caution when departing their crime scene (Davies et al., 1997).

Conclusion

As can be seen from the current study, when studying rare or unusual crimes such as sexual homicide, police databases can provide a level of data not currently available elsewhere. Moreover, with the sample size of our study, we were able to provide a more accurate and representative portrait of sexual murderers and their crimes in Canada than has previously been offered. The current study uncovers very important differences that could prove useful for the investigation and profiling of these crimes by the police.

Although this study provides some novel information on sexual murders, it is not without its limitations. Perhaps the most obvious limitation is the nature of the data. Police databases are a useful source of data, which provide a significant amount of details relating to the offense. However, such data offers very little information about the offenders themselves. This is why clinical studies such as those from Proulx et al. (2007) and Beech and colleagues (2005) are needed to complement the portrait of the sexual murderer provided by police data. Another limitation is related to the nature of sexual homicide. No legal definition of sexual homicide exists; as such, the identification of such cases rests on the police investigators’ shoulders. However, it is quite possible that the sexual nature of some homicides go unnoticed because of the absence of forensic evidence (e.g., semen) or because the offender never revealed his true motive for the crime. Therefore, despite our attempt to present the most complete picture of the sexual murderer and his crime, it may well be that some cases have still evaded us.

Nonetheless, the current study offers a very detailed portrait of the sexual murderer and his or her crime with probably the most extensive database existing in Canada. Future studies should use the available data to replicate some of the published studies on the topic (e.g., the typologies) as well as examining specific aspects of offender behavior. One area that deserves such attention is offenders’ use of forensic awareness strategies to avoid detection.

Footnotes

Authors’ Note

The views expressed are those of the authors and are not necessarily those of the Royal Canadian Mounted Police.

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) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by a grant (SSHRC # 410-2011-1794) from the Social Sciences and Humanities Research Council Small Research Grant.

Notes

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