Adult Male-on-Female Stranger Sexual Homicide

Abstract

Research into stranger sexual homicide remains limited as is our understanding of this crime, and this can hinder criminal investigations and the assessment and management of offenders. This study aims to address this. Using data gathered by various British police forces, this study presents a descriptive profile of adult male-on-female stranger sexual homicide in Great Britain in recent years. Along with demographic and occupational data on offenders and victims, the criminal histories of offenders are illustrated as are their offense behaviors. The results are discussed in light of similar research, and future directions and implications are considered.

Keywords

sexual homicide stranger victim/offender relationship criminal careers profiling policing crime scene

Introduction

Sexual homicide is a distinctive form of homicide and an extreme form of sexual violence. Such crimes can involve murder or manslaughter; intentional or accidental killings, rape or other sexual assaults that escalate into homicide; angry and violent assaults in which homicide or serious harm was intended or reasonably foreseen; sadistic assaults where homicidal violence was eroticized; homicides that involve post-mortem sexual behavior toward the deceased; other displays of sexual deviancy; and other, sometimes, motiveless killings that ultimately are found to contain covert sexual dynamics (Greenall, 2012). Although most sexual homicides are committed by men and most victims are female, offenders and victims come from all ages and both genders (Beauregard & Martineau, 2013; Roberts & Grossman, 1993).

The diverse nature of sexual homicide has encouraged researchers to highlight certain sub-types of this crime. These have illustrated differences in victims (i.e., males—Beauregard & Proulx, 2007; children—Beauregard, Stone, Proulx, & Michaud, 2008; and the elderly—Safarik, Jarvis, & Nussbaum, 2000) and offenders (i.e., females—Chan & Frei, 2013; juveniles—Chan, Heide, & Myers, 2013; psychopathic—Porter, Woodworth, Earle, Drugge, & Boer, 2003; and organized-disorganized—Ressler, Burgess, & Douglas, 1988). Other studies have illustrated the differing motivations of sexual homicide (Chan & Heide, 2009; Kerr, Beech, & Murphy, 2013) and the circumstances in which the killing occurs (Greenall, 2012). Although these studies address the diversity of sexual homicide, one sub-type that has not been examined in detail involves adult male-on-female strangers. The present study addresses this by exploring this particular type of sexual homicide using a British sample.

Stranger Sexual Homicide

Research suggests a minority of homicides (circa 1%-5%) are sexual (see Greenall, 2012). Some studies (e.g., Carter, Mann, & Wakeling, 2008; Grubin, 1994; Langevin, Ben-Aron, Wright, Marchese, & Handy, 1988; Porter et al., 2003) suggest most sexual homicides involve strangers, whereas others (e.g., Abrahams et al., 2008; Chan et al., 2013; Greenfeld, 1997; Häkkänen-Nyholm, Repo-Tiihonen, Lindberg, Salenius, & Weizmann-Henelius, 2009) suggest this is only the case for a minority of victims. Although not formally defined, stranger sexual homicide can occur “where victims have no previous knowledge of the offender, had not knowingly met them before and would, therefore, be unable to name them or provide information about their identity” (Criminal Justice Joint Inspection, 2012, p. 29).

From an investigative perspective, stranger sexual homicide presents two important challenges. The first involves suspect identification and the fact that victims are unable to tell their story to aid this process. The second relates to the fact that many detectives may have little or no knowledge and experience of such crimes, and this may hinder the investigation (Adhami & Browne, 1996). In Great Britain, policing guidance states that investigative knowledge “assists investigators to make effective and accountable decisions . . . [and] . . . identify and bring offenders to justice” (Association of Chief Police Officers, 2005, p. 18). Investigative knowledge includes several areas including the characteristics of the crime, such as modus operandi and information relating to victims and offenders. To develop investigative knowledge of adult male-on-female stranger sexual homicide, an evidence base is required. This would allow detectives to formulate hypotheses about potential suspects, provide greater understanding of the case and the offender, and justify investigative decisions (Cole & Brown, 2011; Copson, 1995).

Within prisons and secure hospitals, the assessment and management of sexual homicide offenders may present further challenges. As Carter et al. (2008) suggest, although sexual killers are a persistent feature of society, the extent to which this type of offense is understood by researchers and criminal justice professionals is limited. In addition, existing therapeutic approaches may (Beech, Oliver, Fisher, & Beckett, 2005) or may not (Tardif, Dassylva, & Nicole, 2007) be relevant to such offenders, and current risk assessment protocols have yet to demonstrate sufficient validity in this area (Hill et al., 2012). This may explain why Tardif et al. (2007) argue, “the treatment of sexual murderers remains a cloudy, if not frankly confusing, issue” (p. 213). Indeed, such are the challenges presented by these offenders that Tardif et al. (2007) go on to suggest “some therapists may refuse to treat sexual murderers” (p. 224). Although the latter is unlikely, such anxieties illustrate the need for further research into sexual homicide, especially when committed by strangers, so as to provide an evidence base that can assist in the comprehensive assessment and formulation of those who commit this rare and devastating crime (Hart & Logan, 2011).

Characteristics of Sexual Homicide

Various studies (Beauregard & Martineau, 2013; Beauregard & Proulx, 2002; Carter & Hollin, 2010; Gerard, Mormont, & Kocsis, 2007; Greenall, 2005, 2012; Grubin, 1994; Häkkänen-Nyholm et al., 2009; Langevin et al., 1988; Roberts & Grossman, 1993) provide a description of the characteristics of sexual homicide. Most are single offender–victim encounters that occur in the victim’s home or a public location. Asphyxiation is a frequent method of killing, although knives, blunt instruments, and hands-on violence are not uncommon, as is excessive violence and mutilation. Sexual activity can occur before, during, or after the killing, and sometimes, evidence of such behavior is absent. From their review of the literature on non-serial sexual homicide, Carter and Hollin (2010) suggest sexual homicide offenders are generally White men in their 20s or 30s who were physically abused and experienced a disturbed relationship with their father. At school, they displayed behavioral problems, were poor achievers, and experienced social isolation. In adulthood, they became isolated single men who abuse substances and have criminal records. Other research suggests victims are generally White females who come from a broader age range but are mostly in their 20s and 30s (Beauregard & Martineau, 2013; Gerard et al., 2007; Greenall, 2005). The occupational backgrounds of victims include various types of formal employment, unemployment, and prostitution. Some victims abuse substances and common pre-homicide activities include domestic duties, jogging/walking, and partying.

Criminal Histories

Nicole and Proulx (2007b) suggest the criminal careers of sexual murderers have not been extensively investigated. Notwithstanding this, research suggests many sexual homicide offenders have previous convictions, for a range of offenses and from an early age (Beauregard & Martineau, 2013; Carter & Hollin, 2010). Although these studies do not concentrate on men who targeted strangers, some indication as to the criminal histories of men who commit similar crimes is available. For example, research has found most stranger rapists have diverse criminal histories (Davies, Wittebrood, & Jackson, 1998; Greenall & West, 2007), and Marogna (2005) found 70% of male-on-female stranger homicide offenders (most of whom were considered to be sexually motivated) had criminal histories.

The Present Study

Proulx, Cusson, and Beauregard (2007) suggest some studies of sexual homicide are weakened by a failure to take into account a number of crucial features, such as victim–offender gender and age. Similarly, Chan and Heide (2009) argue that mixing victim types seriously limits the extent to which any conclusions can be drawn. Although various victim–offender relationships are reported within the sexual homicide literature, one sub-type that has not been examined in detail involves adult male-on-female strangers. The present study addressed this with the following research questions:

Research Question 1: When considering factors such as offender and victim demographics, location, and sexual and violent acts committed, what are the characteristics of adult male-on-female stranger sexual homicide?

Research Question 2: What are the criminal histories of men who commit this type of homicide?

Method

This research involved a retrospective analysis of historical data supplied by the National Crime Agency (NCA). The NCA is a national law enforcement agency that tackles serious and organized crime throughout the United Kingdom. Data were held by the NCA’s Serious Crime Analysis Section (SCAS) at Bramshill in Hampshire. The SCAS receives case information from a network of officers employed in intelligence departments in every British police force. This information is coded by analysts onto a Violent Crime Linkage Analysis System (ViCLAS) database originally developed in Canada. Using ViCLAS, SCAS analyzes rape and serious sexual assaults and motiveless or sexually motivated murders and can provide assistance to detectives investigating such crimes (see www.nationalcrimeagency.gov.uk).

Selection Criteria

Cases were extracted from ViCLAS by SCAS based on the following criteria. First, all were solved male-on-female stranger homicides, where the offender and victim were adults. For the purposes of this study, adult is defined as aged 16 or above as this is the age of sexual consent within Great Britain. Second, all cases contained evidence of overt sexual behavior (e.g., vaginal or anal penetration) and/or other behaviors suggesting the homicide contained a sexual element (e.g., victim’s clothing removed or disturbed). This process yielded a data set of 81 non-serial, single offender–victim, adult male-on-female stranger sexual homicides that occurred within Great Britain between 1970 and 2010.

Analysis

The data supplied by the NCA were transferred into SPSS to determine frequencies. The data were categorical and the coding used by SCAS meant some variables had very low frequencies. To address this, we combined some low frequency variables into new higher frequency variables.

Results

Offender and Victim Demographics

Age and ethnicity

Offender ages at the time of the homicide ranged from 16 to 54 years (M = 30.6, SD = 8.9). The biggest group was aged 20 to 29 years, and almost half (48%) were under 30. The age of the victims ranged from 16 to 93 years (M = 36.5, SD = 20.8), but similar to their assailants, the biggest group was 20 to 29 years and just over half (53%) were under 30. Unlike their assailants, however, some victims (16%) were aged 60 or above (see Figure 1). Although the mean age of the victims was higher than their assailants, the difference failed to reach the adjusted significance (t = −2.37, p = .019).¹

Figure 1.

Offender and victim ages.

In just over half of the cases (52%), victims were killed by younger men. In only one case, the offender and victim were the same age. Offender–victim age differentials ranged from 0 to 72 years (M = 17.6, SD = 16.1). In most cases (64%), the age difference was 10 years or more, and in almost a third (30%), it was 20 years or more. Because the median victim age was 29 years, victims were divided into under and above 30 groupings. Among the under 30 victim group, ages ranged from 16 to 29 years (M = 22.4, SD = 4.2). Their assailants had a broader age range of 18 to 54 years (M = 31.7, SD = 9.1) and were significantly older (t = −6.11, p < .000). Among the above 30 victim group, ages ranged from 30 to 93 years (M = 52.6, SD = 20.4). Their assailants had a narrower age range of 16 to 51 years (M = 29.3, SD = 8.7) and were significantly younger (t = 6.45, p < .000). The finding that victims under 30 were more likely (79%) to be killed by offenders older than themselves, whereas victims above 30 were more likely (89%) to be killed by offenders younger than themselves, reached significance (χ² = 40.6, p < .001).

Most offenders and victims (90% of both) originated from a White ethnic background, and the rest came from various Black and minority ethnic groupings . In 76 cases, the ethnic status of offenders and victims were known. Seven offenders originated from a Black or minority ethnic background, and they all victimized White women. Among the 69 offenders from a White background, 94% victimized White women. Of the 76 cases with known ethnic status therefore, a significant number were intra- (n = 65) rather than inter- (n = 11) racial (χ² = 38.4, p < .000).

Occupational status

The current or most recent occupation of 56 victims was known, and the majority (n = 34) had some form of employment. Among the posts held, the sex industry was the most common occupation followed by jobs involving “positions of trust” (e.g., teacher, caregiver). Women not in employment (n = 22) were retired, students, or unemployed. In terms of vulnerability/risk, by virtue of their involvement in the sex industry, some forms of employment (i.e., “public access” in retail, catering) and/or by leading a student lifestyle, many victims were engaged in activities that brought them into contact with members of the public and potential assailants.

The current or most recent occupation of 39 offenders was known, and the majority (n =25) had some form of employment. Among the posts held, static (e.g., factory worker) and mobile (e.g., taxi driver, construction) employment were the most common occupations. All the offenders without employment were unemployed. Similar to their victims, many offenders were engaged in activities (e.g., mobile employment, “public access” in catering) that brought them into contact with members of the public and potential victims (see Table 1).

Table 1.

Current/Most Recent Occupation.

	Offenders		Victims
Status	(n = 39)	%	(n = 56)	%
Employed	25	64	34	61
Military	2	8
Mobile employment	9	36
Office worker			3	9
Other			1	3
Position of trust			6	18
Public access	2	8	3	9
Sex trade			20	59
Static employment	12	48	1	3
Not employed	14	36	22	39
Housewife			1	5
Retired			11	50
Student			7	32
Unemployed	14	100	3	14

Criminal Histories

The criminal histories of the offenders suggest there are two sub-groups of adult male-on-female stranger sexual homicide offenders. First are those with no previous convictions, and stranger sexual homicide was their first known offense (36%, n = 29). Second are those with previous convictions, and stranger sexual homicide was an act of recidivism (64%, n = 52). The age of the recidivists at first conviction ranged from 10 to 31 years (M = 17.6, SD = 5.2) and collectively, they had 1,344 previous convictions, ranging from 1 to 138 (M = 26, SD = 38.3). A breakdown of these convictions is presented in Table 2 and suggests that the majority were not of a serious nature. For example, 68% involved theft and miscellaneous offenses, 6.5% involved violent or sexual offenses, and 2.8% involved public order or weapons offenses. Table 2 also shows the percentages of offenders with certain types of previous convictions. For example, the biggest single category was theft followed by property offenses; 28% had previous convictions for violence, and 16% had previous convictions for sexual offenses.

Table 2.

Offender Criminal Histories.

	Recidivists (n = 52)		Total sample %	Offenses
	n	%	(N-81)	(n = 1,344)	%
Previous convictions
Theft	45	87	56	628	47
Property	24	46	30	119	9
Violence	23	44	28	61	4.5
Police courts prisons	23	44	28	99	7
Fraud	22	42	27	97	7
Miscellaneous	15	29	18.5	280	21
Sexual	13	25	16	23	2
Public order	12	23	15	22	2
Weapons	6	12	7	11	0.8
Drugs	2	4	2.5	4	0.3

Circumstances of the Offense

Location and timing

Just over half (53%) of the homicides occurred outdoors in roads, streets, alleyways, fields, or parks. The rest occurred indoors, mostly in the victim or offender’s residence. Among all of the locations, the single most common was the victim’s residence (31%; see Table 3). ViCLAS records the day the homicides occurred and, in some cases, the time they commenced. More homicides were committed on a Friday than any other day, and 71% occurred between Thursday and Sunday, suggesting a weekend aspect to this crime. In 78 cases, the time the homicide commenced was recorded. By assigning the commencement time to an appropriate 3-hr time zone, Table 3 shows a clear pattern of escalation during the course of the day. From 6 a.m., the number of homicides increases to a peak from 9 p.m. to midnight, following which the numbers decline. The finding that the majority of homicides (54%) commenced between 9 p.m. and 3 a.m. suggests a nighttime aspect to this crime.

Table 3.

Circumstances of the Offense.

	(n = 81)	%
Indoors
Victim’s residence	25	31
Offender’s residence	10	12
Business/retail	2	2.5
Public area	1	1
Outdoors
Public open space	18	22
Road/street/alley	16	20
Offenders’ residence	1	1
Farm	1	1
Other	7	9
Days	(n = 81)	%
Monday	6	7
Tuesday	10	12
Wednesday	7	9
Thursday	15	18.5
Friday	19	23.5
Saturday	14	17
Sunday	10	12
Times	(n = 78)	%
12 a.m.-3 a.m.	17	22
3 a.m.-6 a.m.	6	8
6 a.m.-9 a.m.	2	3
9 a.m.-12 p.m.	2	3
12 p.m.-3 p.m.	5	6
3 p.m.-6 p.m.	10	13
6 p.m.-9 p.m.	11	14
9 p.m.-12 a.m.	25	32

Offense Behaviors

Violent acts

In 53 cases (65%), one or more weapons were used, with a ligature being the single most common type. In many cases, weapons were obtained from the crime scene (n = 25), although in others, the offenders brought the weapon with them (n = 15). In several cases, multiple causes of death were recorded. The most common was asphyxiation by ligature or manual strangulation. Others received head injuries or were stabbed/cut/slashed in one or more parts of the body. In some cases, the level of violence appeared excessive as 84% of victim injuries were coded as severe and 14% were coded as extreme (see Table 4).²

Table 4.

Offense Behaviors.

	(n = 81)	%
Violent behaviors
Severe injuries inflicted	68	84
Victim asphyxiated	47	58
Ligature weapon	29	36
Weapon obtained at crime scene	25	31
Stabbing weapon	24	30
Victim had head injury	24	30
Other injuries	19	23.5
Victim stabbed/cut/slashed	16	20
Weapon brought by offender	15	18.5
Extreme injuries inflicted	11	14
Bludgeoning weapon	8	10
Other weapon	7	9
Sexual behaviors
Victim stripped naked	33	41
Victim partially disrobed	22	27
Vaginal penetration	21	26
Sexual assault by penetration	21	26
Victim’s genitals exposed	20	25
Other sexual acts committed	17	21
Multiple penetrations	15	18.5
Anal penetration	13	16
Victim engaged sexually	13	16
Offender disrobed victim	11	14
Oral penetration	6	7
Other behaviors
Body left exposed	45	56
Precautions taken	31	38
Body concealed	28	35
Body moved from crime scene	17	21
Victim’s clothing ripped/torn	16	20
Disabled the victim	13	16

Sexual acts

The sexual behaviors committed by the offenders again suggest there are two sub-groups of adult male-on-female stranger sexual homicide offenders. First is an overt sexual group whose homicides evidenced sexual behavior with their victims (63%, n = 51). Because of the low frequency of some behaviors, they were combined into those displayed in Table 4 using the definitions in the Sexual Offences Act 2003 as a guide. As shown, a sizable minority of victims were raped, sexually assaulted by penetration (digital and/or foreign object), or were subjected to other sexual acts that could constitute indecent assault. Some victims reportedly had more than one body orifice sexually penetrated, and others engaged sexually with their assailant during the assault. This engagement reportedly included acts such as hugging and/or kissing their assailant and/or undressing themselves, presumably all at the offender’s instigation.

Second is a covert sexual group whose homicides did not evidence sexual behavior with their victims (37%, n = 30). Rather, the sexual aspects of these homicides are inferred by the removal and/or disturbance of the victim’s clothing, such that the victim’s breasts and/or genitalia were partially or totally exposed. The sexual nature of some homicides is illustrated by the fact that 14% of offenders are reported to have undressed their victim themselves. However, the hurried, angry, or confrontational nature of others (20%) is illustrated by the victim’s clothing being cut, ripped, or torn. Others (30%) were less frenetic as the victim’s clothing was undamaged.

Other behaviors

Some homicides included actions to aid the conduct of the crime and/or to avoid detection. Because of the low frequency of some actions, they were combined into those displayed in Table 4. Some offenders took steps to disable their victim, such as gagging, blindfolding, tying the victim up, or disabling their telephone (16%). In addition, 38% of offenders took various precautions. These included acts to hide their identity such as wearing a disguise, gloves, or mask, using a false name, or even disguising their car. Other precautions included wearing a condom and actively destroying forensic evidence. After the homicide, 21% of offenders moved the body from the crime scene to another location. When the victim was abandoned, 56% made no effort to hide the body and simply left it exposed for others to find whereas 35% made some effort to conceal the body, such as leaving it in water or partially or completely buried.

Discussion

At its most basic level, sexual homicide can be viewed as resulting from the crimes of homicide and sexual violence coalescing into one single act or during one single assault (Greenall, 2012). By viewing the findings of this study in relation to the research on these crimes plus sexual homicide generally, we can begin to establish whether adult male-on-female stranger sexual homicide has any unique features.

Demographics

Victim ages covered the full range, including some aged 60 or above who could be regarded as elder (stranger) sexual homicides (Safarik et al., 2000). Offenders were concentrated into a narrower range with a higher proportion in their 20s and 30s. These findings mirror research into homicide (Cooper & Smith, 2011; Francis et al., 2004), sexual offending (Greenall & West, 2007; Muir & Macleod, 2003), and sexual homicide (Gerard et al., 2007; Greenfeld, 1997; Häkkänen-Nyholm et al., 2009). More specifically, they support previous research (Shackelford, 2002) that found young, reproductive-aged females to be over-represented as victims of sexual homicide, whereas young men were similarly over-represented among offenders. Most homicides were intra-racial, which again reflects research into homicide (Cooper & Smith, 2011; Francis et al., 2004), sexual offending (Muir & Macleod, 2003), and sexual homicide (Chan, Myers, & Heide, 2010; Greenfeld, 1997; Grubin, 1994; Van Patten & Delhauer, 2007). Therefore, in relation to the basic demographics, adult male-on-female stranger sexual homicide appears typical when compared with other crimes.

When offender–victim ages were considered together, a notable dynamic was found. Not only was there a large age differential in most cases, but women under 30 were more likely to be killed by men older than themselves, whereas women above 30 were more likely to be killed by men younger than themselves. Young women are sexually killed by older men for various reasons, including sexual desire. Therefore, along with intentional killings, these attacks may have begun as sexual assaults but progressed to homicide (Greenall, 2012). This idea is supported by Shackelford (2002) who found that the over-representation of young, reproductive-aged females as victims of sexual homicide could not be solely attributable to their greater association with young men. Be that so, how can we explain the finding that women above 30 are more likely to be sexually killed by younger men? Some men may specifically target older women to sexually assault and/or kill (Safarik et al., 2000), whereas for others, the sexual assault of an elderly female may have been secondary to burglary (Chan & Heide, 2009). Alternatively, whereas a sexual assault may have been intended, the killing may not have been. However, when sexual assaults include violence, the line between violence and homicide can easily be crossed (Greenall, 2012). This may be especially so if the victim is elderly and less able to survive a violent attack.

A majority of offenders and victims had some form of employment. In most cases, this brought them into contact with the public and potential victims and assailants. A notable finding as far as victims are concerned is the high number involved in prostitution. This mirrors research into sexual homicide (Beauregard & Martineau, 2013; Gerard et al., 2007; Van Patten & Delhauer, 2007), and although it could be argued that prostitute homicides should be examined separately (Salfati, James, & Ferguson, 2008), they were not excluded from this study. Consequently, it appears certain types of employment are risk factors for stranger sexual homicide as they provide opportunities for offenders to identify potential victims and to note patterns in their activities.

Criminal Histories

Similar to research on homicide (Francis et al., 2004; Soothill, Francis, Ackerley, & Fligelstone, 2002), sexual offending (Soothill et al., 2002) and stranger sexual and homicidal violence (Davies et al., 1998; Greenall & West, 2007; Marogna, 2005), most offenders had previous convictions and some had extensive criminal histories. However, only a minority had previous convictions for sexual and violent offenses. It appears therefore that many stranger sexual killers are, to paraphrase Scully’s (1990) description of rapists, typical offenders with no remarkable criminal history to suggest a greater likelihood to sexually assault and kill adult female strangers.

This study also found a sizable minority of offenders without previous convictions. On the one hand, this finding is unremarkable as research into homicide has found similar percentages of offenders without previous convictions (Francis et al., 2004; Soothill et al., 2002). On the other hand, if we accept Schlesinger’s (2004a, 2004b) argument that most homicides are situationally determined (i.e., reactions to external stress), we can understand how many homicide offenders have no previous convictions but still wonder how an individual’s first offense could be a sexual killing of a female stranger. It is possible that such men had previously engaged in criminal behavior without being apprehended. For example, Greenall and West (2007) found that most stranger rapists had engaged in antisocial conduct that could have resulted in conviction. Alternatively, these men may have engaged in various pre-offense activities (e.g., burglary, stalking, or other “behavioral try-outs”) that ultimately evolved into an offense script upon which they acted (MacCulloch, Snowden, Wood, & Mills, 1983). However, applying this logic here is speculative as this study suggests that, as in non-sexual homicide, about a third of those who commit adult male-on-female stranger sexual homicide will not have previous convictions.

A Profile of Adult Male-on-Female Stranger Sexual Homicide

Just over half of the homicides occurred outdoors although many took place in the victim’s residence. This contrasts with research into homicide as Brookman (2005) reports most cases in Great Britain occur in a house with only a minority occurring outside. However, research into stranger rape (Greenall & West, 2007) and sexual homicide (Beauregard & Martineau, 2013; Grubin, 1994; Langevin et al., 1988; Roberts & Grossman, 1993) suggest victims’ residences and public places are typical locations. Most homicides occurred at night and on weekends. This mirrors research into sexual offending. For example, Greenfeld (1997) found 77% of rapes and sexual assaults occurred between 6 p.m. and 6 a.m.; Ruparel (2004) found most rapes occurred between 9 p.m. and 4 a.m. and most stranger rapes occurred between Friday and Saturday; and Feist, Ashe, Lawrence, McPhee, and Wilson (2007) found the number of rapes rose during the week to a peak on Saturdays. Therefore, in relation to when they offend, it appears this sample is similar to other sexual offenders.

From these findings, we can hypothesize that many adult male-on-female stranger sexual homicides are associated with or are preceded by the consumption of alcohol and/or drugs as this is a common activity at evenings and weekends. Indeed, research into homicide (Brookman, 2005; Brookman & Maguire, 2003), stranger rape (Greenall & West, 2007), and sexual homicide (Beech et al., 2005; Carter & Hollin, 2010) suggests many offenders were intoxicated at the material time. In addition, Beauregard and Martineau (2013) found sizable minorities of sexual homicide victims abuse alcohol or drugs. Ruparel (2004) found that 49% of rapes where the victim consumed alcohol were committed by strangers, and victims who had consumed alcohol were more likely to be raped on a Friday, Saturday, or Sunday. Consequently, some adult male-on-female stranger sexual homicides appear impulsive, opportunistic acts undertaken by intoxicated men against vulnerable intoxicated women. Alternatively, the fact that the victim’s residence is a popular location suggests others may occur in the context of crimes such as burglary (Mouzos, 2003; Pedneault, Harris, & Knight, 2012; Schlesinger & Revitch, 1999).

Similar to research into homicide (Brookman & Maguire, 2003; Francis et al., 2004; Osborne, 2012), stranger rape (Greenall & West, 2007), and sexual homicide (Beauregard & Martineau, 2013; Chan & Heide, 2008; Chan et al., 2013; Gerard et al., 2007; Häkkänen-Nyholm et al., 2009; Langevin et al., 1988; Nicole & Proulx, 2007a), most cases involved a weapon. The fact that weapons were mostly obtained from the crime scene supports the idea that many offenses were opportunistic, or at least the killings were. Most homicides were particularly violent and some were especially so. Asphyxiation was the most common method of killing, although head injuries and stabbings were not uncommon. The method of killing contradicts British research into homicide (Osborne, 2012) that shows that for many years, the most common method of killing both sexes has been with a sharp instrument; asphyxiation has only ever been the second most common method of killing women. However, several studies into sexual homicide have found asphyxiation to be a common method of killing (Beauregard & Martineau, 2013; Carter & Hollin, 2010; Häkkänen-Nyholm et al., 2009; Smith, Basile, & Karch, 2011; Van Patten & Delhauer, 2007), and Grubin and Gunn (1990) found that where deaths occur in rape, 70% involved strangulation. The high prevalence of asphyxiation within sexual homicide may be due to it being a “close up and personal” method of killing that Schlesinger (2004b) argues “occurs because the offender can control the length of time necessary to cause death and concomitantly increase his sexual gratification” (p. 239).

In most cases, the sexual aspects of the homicides were clear as victims were subjected to a range of sexual acts. In others, the sexual element appeared less overt and a sexual element was inferred from clothing being removed and/or disturbed. Along with sexual and violent behaviors, some offenders engaged in acts aimed at assisting with the execution of the crime and/or avoiding detection. For example, some offenders moved the body from the crime scene to another location, thereby creating multiple crime scenes and making their detection harder. Such acts suggest these offenders were organized individuals (Beauregard & Field, 2008; Ressler et al., 1988) who planned the assault and how to behave afterward. However, in most cases, the body was left abandoned for all to see, suggesting either that the offenders gave no thought to avoiding detection or wanted the body to be found (Holmes & Holmes, 2002).

Implications and Future Directions

Although descriptive in nature, the findings of this study have investigative potential. For example, although not suggesting young women are sexually killed by older men and vice versa, the findings in relation to age differentials could allow detectives to focus on suspects who are older or younger than the victim, depending on her age. These findings, however, are preliminary and the significance of age warrants further investigation. Along with age, the occupational findings are noteworthy as they suggest an understanding of employment patterns can illustrate the type of people a victim met, when, and how often.

The criminal history findings are disturbing and encouraging. They are disturbing because they suggest a sizable minority of stranger sexual killers have no previous convictions and therefore will be unknown to the police. This renders the task of suspect prioritization based on previous criminality much harder. This study is encouraging as it suggests most stranger sexual killers have criminal histories and will therefore be known to the police. Unfortunately, the low levels of previous sexual and violent criminality suggest an investigative strategy based on prioritizing known sexual and/or violent offenders may prove unproductive. Further research, however, could aid the process of suspect prioritization. For example, Porter et al. (2003) found sexual homicides committed by offenders with a diagnosis of psychopathy in Canada included higher levels of violence. Given that such offenders are considered to have varied criminal histories (Hare, 2003), further research on this sample will explore whether especially violent stranger sexual homicides are committed by men with varied criminal histories. Another area of future exploration is whether detectives can differentiate between offenders with and without criminal histories. Once again, this sample can assist in providing an answer by exploring the demographic, circumstantial, and behavioral differences between such men. These are just two examples of how the relationship between offense behaviors and previous histories among this sample will be explored to aid future criminal investigations (Canter, 2011).

The findings of this study also have clinical implications. Research suggests sexual homicide offenders may be similar to other offenders in many ways (Kerr et al., 2013; Proulx, Beauregard, Cusson, & Nicole, 2007). This study suggests this may also apply to stranger sexual killers. In addition, the offenders in this study arguably evidenced several risk factors for future violence. These include having an antisocial criminal orientation (Hanson & Bussière, 1998; Hanson & Morton-Bourgon, 2004), histories of non-sexual criminality (Hart et al., 2003), targeting strangers (Hanson & Thornton, 2003; Thornton et al., 2003), and using physical coercion in sexual violence (Hart et al., 2003). Indeed, the high levels of violence in some homicides may have evidenced sadism or anger/hatred (Greenall, 2012) and been committed by psychopathic individuals (Porter et al., 2003). Other homicides appeared more sexual and perhaps evidenced sexual deviancy by the usage of bindings or asphyxiation. Such factors are important treatment targets that can be explored in detail within clinical practice (Beech et al., 2005; West & Greenall, 2011). Finally, both for clinical and investigative purposes, previous research has illustrated the motivational and behavioral diversity of sexual homicide offenders (Chan & Heide, 2009; Gerard et al., 2007; Greenall, 2012; Kerr et al., 2013; Kocsis, Cooksey, & Irwin, 2002; Lundrigan, 2009). Further research on this sample will explore whether such diversity exists among stranger sexual killers.

Limitations and Conclusion

Although this study has produced some notable findings, the potential shortcomings need to be acknowledged. First, in wanting to be a “pure” study of sexual homicide involving adults, a cutoff age of 16 years was used. This contradicts studies that have defined adult women as 14 years and above (see Chan & Heide, 2009) and adult men as 18 years and above (e.g., Chan & Heide, 2008). However, “adult” can have various definitions, based on when people can marry, vote, consume alcohol, join the Armed Forces, or drive a car. In Great Britain, people are not adults in a sexual sense until they reach the age of 16 (as the legal age of consent); hence, why this age was chosen.

Second, although the NCA serves every British Police Force, they are reliant on Forces to provide accurate data. As Martineau and Corey (2008) state, the quality of data contained within databases like ViCLAS can also affect the quality of research conducted using them. Given that victims can provide a great deal of information about a crime, the inability of homicide victims to tell their story means that police officers will have to extrapolate information from the crime scene or rely on the accounts of witnesses who may have limited exposure to the victim, offender, or offense (Martineau & Corey, 2008). Consequently, there is always a danger that research using such data may contain some inaccuracies. This will apply to the current study and some of its findings such as sexual behaviors and the reported engagement of the victim with her assailant. However, this is an inevitable feature of this type of research. Having said that, Martineau and Corey suggest that databases like ViCLAS actually provide reliable data for research purposes. As such, further research on this sample will enhance our understanding of this devastating crime and those who commit it with the goal of providing a sound evidence base from which to draw.

Footnotes

Acknowledgements

The authors are grateful to Lee Rainbow, Meriel Kurton, and Sarah Galambos, from the NCA at Bramshill in Hampshire, for their valuable assistance with this research. In addition, we would like to thank Dr. Caroline Logan from the Edenfield Centre of Prestwich Hospital in Manchester, Dr. Michelle Wright from Manchester Metropolitan University, the NCA’s Research Panel, and the reviewers of Homicide Studies, for their comments on earlier drafts of this article.

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.

Notes

Author Biographies

Paul V. Greenall is a Forensic Psychologist in Training at the Edenfield Centre medium secure unit in Manchester and a PhD student at Manchester Metropolitan University.

Clare Richardson is a Chartered Psychologist (British Psychological Society), and is registered with the Health Professions Council as a Practitioner Psychologist (Forensic). She holds both academic and clinical positions. Her area of expertise is risk assessment and management of offenders.

References

Abrahams

Martin

L. J.

Jewkes

Mathews

Vetten

Lombard

(2008). The epidemiology and the pathology of suspected rape homicide in South Africa. Forensic Science International, 178, 132-138.

Adhami

Browne

D. P.

(1996). Major crime enquiries: Improving expert support for detectives (Special Interest Series Paper 9). London, England: Home Office.

Association of Chief Police Officers. (2005). Practice advice on core investigative doctrine. Cambourne, UK: National Centre for Policing Excellence.

Beauregard

Field

(2008). Body disposal patterns of sexual murderers: Implications for offender profiling. Journal of Police and Criminal Psychology, 23, 81-89.

Beauregard

Martineau

(2013). A descriptive study of sexual homicide in Canada: Implications for police investigation. International Journal of Offender Therapy and Comparative Criminology, 57, 1454-1478.

Beauregard

Proulx

(2002). Profiles in the offending process of nonserial sexual murderers. International Journal of Offender Therapy and Comparative Criminology, 46, 386-399.

Beauregard

Proulx

(2007). A classification of sexual homicide against men. International Journal of Offender Therapy and Comparative Criminology, 51, 420-432.

Beauregard

Stone

M. R.

Proulx

Michaud

(2008). Sexual murderers of children: Developmental, precrime, crime, and postcrime factors. International Journal of Offender Therapy and Comparative Criminology, 52, 253-269.

Beech

Oliver

Fisher

Beckett

(2005). STEP 4: The sex offender treatment programme in prison: Addressing the offending behaviour of rapists and sexual murderers. London, England: Her Majesty’s Prison Service.

10.

Brookman

(2005). Understanding homicide. London, England: SAGE.

11.

Brookman

Maguire

(2003). Reducing homicide: A review of the possibilities (Online Report 01/03). London, England: Home Office.

12.

Canter

D. V.

(2011). Resolving the offender “profiling equations” and the emergence of an investigative psychology. Current Directions in Psychological Science, 20, 5-10.

13.

Carter

A. J.

Hollin

C. R.

(2010). Characteristics of non-serial sexual homicide offenders: A review. Psychology, Crime & Law, 16, 25-45.

14.

Carter

A. J.

Mann

R. E.

Wakeling

H. C.

(2008). Sexual killers and post mortem sexual interference offenders: Assessment, treatment, and risk management. In Harris

A. J. R.

Pagé

C. A.

(Eds.), Sexual homicide and paraphilias: The Correctional Services of Canada’s expert forum 2007. Ottawa, Ontario: Correctional Services of Canada. Available from http://www.csc-scc.gc.ca/research/shp2007-paraphil01-eng.shtml

15.

Chan

H. C.

Frei

(2013). Female sexual homicide offenders: An examination of an underresearched offender population. Homicide Studies, 17, 96-118.

16.

Chan

H. C.

Heide

K. M.

(2008). Weapons used by juveniles and adult offenders in sexual homicides: An empirical analysis of 29 years of U.S. data. Journal of Investigative Psychology and Offender Profiling, 5, 189-208.

17.

Chan

H. C.

Heide

K. M.

(2009). Sexual homicide: A synthesis of the literature. Trauma, Violence, & Abuse, 10, 31-54.

18.

Chan

H. C.

Heide

K. M.

Myers

W. C.

(2013). Juvenile and adult offenders arrested for sexual homicide: An analysis of victim–offender relationship and weapon used by race. Journal of Forensic Sciences, 58, 85-89.

19.

Chan

H. C.

Myers

W. C.

Heide

K. M.

(2010). An empirical analysis of 30 years of U.S. juvenile and adult sexual homicide offender data: Race and age differences in the victim-offender relationship. Journal of Forensic Sciences, 55, 1282-1290.

20.

Cole

Brown

(2011). What do senior investigating police officers want from behavioural investigative advisers? In Alison

Rainbow

(Eds.), Professionalizing offender profiling: Forensic and investigative psychology in practice (Kindle–iPad version; pp. 191-205). Abingdon, UK: Routledge.

21.

Cooper

Smith

E. L.

(2011). Homicide trends in the United States, 1980-2008. Washington, DC: U.S. Department of Justice.

22.

Copson

(1995). Coals to Newcastle? Part 1: A study of offender profiling (Special Interest Series Paper 7). London, England: Home Office.

23.

Criminal Justice Joint Inspection. (2012). Forging the links: Rape investigation and prosecution: A joint review by HMIC and HMCPSI. London, England: HMIC/HMCPSI.

24.

Davies

Wittebrood

Jackson

J. L.

(1998). Predicting the criminal record of a stranger rapist (Special Interest Series Paper 12). London, England: Policing & Reducing Crime Unit.

25.

Feist

Ashe

Lawrence

McPhee

Wilson

(2007). Investigating and detecting recorded offences of rape (Online Report 18/07). London, England: Home Office.

26.

Francis

Barry

Bowater

Miller

Soothill

Ackerley

(2004). Using homicide data to assist murder investigations (Online Report 26/04). London, England: Home Office.

27.

Gerard

Mormont

Kocsis

R. N.

(2007). Offender profiles and crime scene patterns in Belgian sexual murders. In Kocsis

R. N.

(Eds.), Criminal profiling: International theory, research, and practice (pp. 27-47). Totowa, NJ: Humana Press.

28.

Greenall

P. V.

(2005). Killing for kicks: An investigation into the phenomenon of sexual homicide (Unpublished). University of Central Lancashire, Preston, UK.

29.

Greenall

P. V.

(2012). Understanding sexual homicide. Journal of Sexual Aggression, 18, 338-354.

30.

Greenall

P. V.

West

A. G.

(2007). A study of stranger rapists from the English high security hospitals. Journal of Sexual Aggression, 13, 151-167.

31.

Greenfeld

L. A.

(1997). Sex offenses and offenders: An analysis of data on rape and sexual assault. Washington, DC: U.S. Department of Justice.

32.

Grubin

(1994). Sexual murder. The British Journal of Psychiatry, 165, 624-629.

33.

Grubin

Gunn

(1990). The imprisoned rapist and rape. London, England: Institute of Psychiatry.

34.

Häkkänen-Nyholm

Repo-Tiihonen

Lindberg

Salenius

Weizmann-Henelius

(2009). Finnish sexual homicides: Offence and offender characteristics. Forensic Science International, 188, 125-130.

35.

Hanson

R. K.

Bussière

M. T.

(1998). Predicting relapse: A meta-analysis of sexual offender recidivism studies. Journal of Consulting and Clinical Psychology, 66, 348-362.

36.

Hanson

R. K.

Morton-Bourgon

(2004). Predictors of sexual recidivism: An updated meta-analysis. Ottawa, Ontario: Public Works and Government Services Canada.

37.

Hanson

R. K.

Thornton

(2003). Notes on the development of Static-2002. Ottawa, Ontario: Department of the Solicitor General of Canada.

38.

Hare

R. D.

(2003). Hare Psychopathy Checklist–Revised (2nd ed.). Toronto, Ontario, Canada: Multi-Health Systems.

39.

Hart

S. D.

Kropp

P. R.

Laws

D. R.

Klaver

Logan

Watt

K. A.

(2003). The Risk for Sexual Violence Protocol (RSVP): Structured professional guidelines for assessing risk of sexual violence. Burnaby, British Columbia, Canada: Simon Fraser University.

40.

Hart

S. D.

Logan

(2011). Formulation of violence risk using evidence-based assessments: The structured professional judgment approach. In Sturmey

McMurran

(Eds.), Forensic case formulation (Kindle–iPad version) (pp. 83-106). Chichester, UK: John Wiley.

41.

Hill

Rettenberger

Habermann

Berner

Eher

Briken

(2012). The utility of risk assessment instruments for the prediction of recidivism in sexual homicide perpetrators. Journal of Interpersonal Violence, 27, 3553-3578.

42.

Holmes

R. M.

Holmes

S. T.

(2002). Profiling violent crimes: An investigative tool. Thousand Oaks, CA: SAGE.

43.

Kerr

K. J.

Beech

A. R.

Murphy

(2013). Sexual homicide: Definition, motivation and comparison with other forms of sexual offending. Aggression and Violent Behavior, 18, 1-10.

44.

Kocsis

R. N.

Cooksey

R. W.

Irwin

H. J.

(2002). Psychological profiling of sexual murders: An empirical model. International Journal of Offender Therapy and Comparative Criminology, 46, 532-554.

45.

Langevin

Ben-Aron

Wright

Marchese

Handy

(1988). The sex killer. Annals of Sex Research, 1, 263-301.

46.

Lundrigan

(2009). A multivariate model of serial sexual murder (Unpublished manuscript). Anglia Ruskin University, Cambridge, UK.

47.

MacCulloch

M. J.

Snowden

P. R.

Wood

P. J. W.

Mills

H. E.

(1983). Sadistic fantasy, sadistic behaviour and offending. The British Journal of Psychiatry, 143, 20-29.

48.

Marogna

(2005). Can criminal antecedent history of a homicide offender be inferred from crime scene behaviours? (Unpublished master’s thesis). University of Leicester, Leicester, UK.

49.

Martineau

Corey

(2008). Investigating the reliability of the Violent Crime Linkage Analysis System (ViCLAS) crime report. Journal of Police and Criminal Psychology, 23, 51-60.

50.

Mouzos

(2003). Homicide in the course of other crime in Australia. Canberra: Australian Institute of Criminology.

51.

Muir

Macleod

M. D.

(2003). The demographic and spatial patterns of recorded rape in a large UK metropolitan area. Psychology, Crime & Law, 9, 345-355.

52.

Nicole

Proulx

(2007a). The factors distinguishing sexual murderers from sexual aggressors: A multivariate analysis. In Proulx

Beauregard

Cusson

Nicole

(Eds.), Sexual murderers: A comparative analysis and new perspectives (pp. 87-97). Chichester, UK: John Wiley & Sons.

53.

Nicole

Proulx

(2007b). Sexual murderers and sexual aggressors: Developmental paths and criminal history. In Proulx

Beauregard

Cusson

Nicole

(Eds.), Sexual murderers: A comparative analysis and new perspectives (pp. 29-50). Chichester, UK: John Wiley & Sons.

54.

Osborne

(2012). Homicide. In Smith

Osborne

Lau

Britton

(Eds.), Homicide, firearm offences and intimate violence 2010/11: Supplementary Volume 2 to crime in England and Wales 2010/11 (Statistical Bulletin 02/12) (pp. 15-53). London, England: Home Office.

55.

Pedneault

Harris

D. A.

Knight

R. A.

(2012). Toward a typology of sexual burglary: Latent class findings. Journal of Criminal Justice, 40, 278-284.

56.

Perneger

T. V.

(1998). What’s wrong with Bonferroni adjustments. British Medical Journal, 316, 1236-1238.

57.

Porter

Woodworth

Earle

Drugge

Boer

(2003). Characteristics of sexual homicides committed by psychopathic and nonpsychopathic offenders. Law and Human Behavior, 27, 459-470.

58.

Proulx

Beauregard

Cusson

Nicole

(2007). Sexual murderers: A comparative analysis and new perspectives. Chichester, UK: John Wiley & Sons.

59.

Proulx

Cusson

Beauregard

(2007). Sexual murderers: Definitions, epidemiology, and theories. In Proulx

Beauregard

Cusson

Nicole

(Eds.), Sexual murderers: A comparative analysis and new perspectives (pp. 9-28). Chichester, UK: John Wiley & Sons.

60.

Ressler

R. K.

Burgess

A. W.

Douglas

J. E.

(1988). Sexual homicide: Patterns and motives. London, England: Simon & Schuster.

61.

Roberts

J. V.

Grossman

M. G.

(1993). Sexual homicide in Canada: A descriptive analysis. Sexual Abuse: A Journal of Research and Treatment, 6, 5-25.

62.

Ruparel

(2004). The nature of rape of females in the Metropolitan Police District (Research Findings 247). London, England: Home Office.

63.

Safarik

M. E.

Jarvis

Nussbaum

(2000). Elderly female serial sexual homicide: A limited empirical test of criminal investigative analysis. Homicide Studies, 4, 294-307.

64.

Salfati

C. G.

James

A. R.

Ferguson

(2008). Prostitute homicides. Journal of Interpersonal Violence, 23, 505-543.

65.

Schlesinger

L. B.

(2004a). Classification of antisocial behavior for prognostic purposes: Study the motivation, not the crime. The Journal of Psychiatry & Law, 32, 191-219.

66.

Schlesinger

L. B.

(2004b). Sexual murder: Catathymic and compulsive homicides. Boca Raton, FL: CRC Press.

67.

Schlesinger

L. B.

Revitch

(1999). Sexual burglaries and sexual homicide: Clinical, forensic, and investigative considerations. Journal of the American Academy of Psychiatry and the Law, 27, 227-238.

68.

Scully

(1990). Understanding sexual violence: A study of convicted rapists. Boston, MA: Unwin Hyman.

69.

Shackelford

T. K.

(2002). Are young women the special targets of rape-murder? Aggressive Behavior, 28, 224-232.

70.

Smith

S. G.

Basile

K. C.

Karch

(2011). Sexual homicide and sexual violence-associated homicide: Findings from the National Violent Death Reporting System. Homicide Studies, 15, 132-153.

71.

Soothill

Francis

Ackerley

Fligelstone

(2002). Murder and serious sexual assault: What criminal histories can reveal about future serious offending (Police Research Series Paper 144). London, England: Home Office.

72.

Tardif

Dassylva

Nicole

(2007). Psychotherapeutic and psychodynamic issues with sexual murderers. In Proulx

Beauregard

Cusson

Nicole

(Eds.), Sexual murderers: A comparative analysis and new perspectives (pp. 213-228). Chichester, UK: John Wiley & Sons.

73.

Thornton

Mann

Webster

Blud

Travers

Friendship

Erikson

(2003). Distinguishing and combining risks for sexual and violent recidivism. Annals of the New York Academy of Sciences, 989, 225-235.

74.

Van Patten

I. T.

Delhauer

P. Q.

(2007). Sexual homicide: A spatial analysis of 25 years of deaths in Los Angeles. Journal of Forensic Sciences, 52, 1129-1141.

75.

West

A. G.

Greenall

P. V.

(2011). Incorporating index offence analysis into forensic clinical assessment. Legal and Criminological Psychology, 16, 144-159.