INTRODUCTION

Sexual homicides began to be studied in 1886, following the publication of ‘Psychopathia Sexualis’ by the German psychiatrist Richard von Krafft-Ebing. It was in this work that he coined the term ‘fatal sadism’ in relation to its occurrence¹. Currently, sexual homicide can be defined as intentional lethal violence with evidence of a sexual element practiced before, during, or after the homicide1, although some authors consider that direct sexual contact is not mandatory when the act of killing becomes the sexual gratification of the perpetrator².

There isn’t a global rate for this crime, and few countries have estimates like South Africa, where there are 3.65 cases per 100,000 adult and adolescent women³. However, there is a consensus that sexual homicide is uncommon and of low prevalence. Additionally, due to its dependency on specific notification and recording in official databases, its numbers are considered uncertain. Despite this limitation, estimates range from 1% of homicides in the United States⁴ to 4% in Canada5. It is believed that the prevalence is significantly higher in countries in armed conflict, primarily against women and children, although with specific and different motivations from other sexual homicides⁴.

Most sexual homicides are committed by male perpetrators^6,7 and the majority of victims are women^8,9. The crime usually involves one perpetrator and one victim, and cases of multiple aggressors or simultaneous multiple victims are uncommon¹⁰. Even less frequent are sexually motivated homicides committed in a serial manner¹¹.

Similar to other violent crimes, sexual homicides can be committed using weapons. However, strangulation, asphyxiation, or beating appear to be more common in sexual homicides^12,13. Men are generally identified as the main perpetrators⁷, with a wide range of thoughts and emotions motivating them for the crime, from planning and choosing the victim to the outcome of an impulsive and furious act^4,14,15. It’s believed that each sexual homicide may contain elements that allow for the distinction of internal dynamics and motivations of the perpetrator^4,16,17.

Studies on sexual homicides have found significant prevalence of psychiatric disorders among perpetrators¹⁸, behavioral disorders^19,20, paraphilias²¹, sadism^9,22, personality disorders^22,23, and a history of traumatic experiences in childhood^23-25. Morphological injuries and functional deficits in certain brain centers are also considered as part of violent behaviors²⁶ and genital abnormalities of the aggressors in childhood^27-29.

There is a lack of data on sexual homicides in Brazil, and the few available studies report situations involving children and adolescents. Nevertheless, there is a growing clinical and medico-legal interest, not only in the characteristics and severity of the violence but also in aspects related to the perpetrator, such as its occurrence against women as sexual femicides. Thus, the aim is to analyze mortality outcomes caused by male perpetrators of sexual homicide against adult individuals.

METHODS

Systematic review of the literature with qualitative metasynthesis, a modality that comprehends and associates qualitative and quantitative findings from studies with different designs, allowing analysis from other perspectives and interpretations. Qualitative meta-synthesis is used in the health sciences because it allows the inclusion of studies with individual experiences in the health-disease process, enabling the assimilation of characteristics of individuals in the face of lived experiences and interpersonal relationships, as indicated in investigations in psychiatry³⁰.

The Patient, Intervention, Comparison, and Outcomes (PICO) strategy was adopted in constructing the research, with the question containing the studied population (male sexual offenders), intervention (homicide of adult victims), context (sexual violence), and outcome (potential relationship between the issues). Therefore, the study population consisted of male perpetrators of sexual homicide, of any age, who committed the crime against adult victims, male or female. Studies involving children and adolescents were excluded. The review’s outcomes of interest were: a) information regarding the psychopathology of the sexual homicide; b) sociodemographic characteristics of the perpetrator and the victim; c) traumatic experiences in the childhood of the perpetrator; d) possibility for reoffending; e) modus operandi of the perpetrator and crime scene; f) type of sexual violence practiced; and g) the form of aggression leading to the lethal outcome.

The search was limited to the interval between 1992 and 2023, the last 30 years, a period with the highest concentration of publications as indicated by Medical Literature Analysis and Retrieval System Online (MEDLINE). Language criteria were not applied for the inclusion or exclusion of articles. The electronic databases of the Scientific Electronic Library Online (SciELO), the Latin American and Caribbean Literature in Health Sciences (LILACS), MENDELEY, and MEDLINE were consulted, using the combination of descriptors (‘Homicide’[Mesh]) AND ‘Sex Offenses’[Mesh].

Original studies on incidence, prevalence, prognosis, diagnosis, observational, screening, cross-sectional, case report, controlled clinical trials, and qualitative research were considered. Review articles, letters or editorials, books or chapters, duplicates, theses, dissertations, monographs, and inaccessible articles were excluded.

The entire process of selecting and analyzing the articles was conducted by two independent researchers, and cases of disagreement regarding inclusion or exclusion were decided upon by a third researcher. In the first stage, 731 articles were identified: 492 in MEDLINE, 193 in MENDELEY, 27 in LILACS, and 19 in SciELO. Screening based on reading titles, abstracts, and population of study resulted in the exclusion of 506 articles. Out of the 225 articles selected for reading, 155 were excluded due to: 86 (55.5%) off-topic; 39 (25.1%) reviews; 11 (7.1%) duplicates; eight (5.2%) books or chapters; five (3.2%) theses; four (2.6%) letters to the editor; and two (1.3%) unavailable articles.

The process concluded with 70 selected articles cataloged using Microsoft Excel^®. Request for payment to access the full text occurred in 49 (70.0%) of the 70 selected articles. The synthesis of the flow, search strategy, and selection process is shown in figure 1. As a systematic review, this article is exempt from submission and approval by the Research Ethics Committee, as per Article 26 of Resolution No. 674, National Commission of Ethics in Research.

Figure 1 : Flowchart of search strategy and article selection for review 

RESULTS

Considering the research designs, 66 articles (94.2%) adopted quantitative designs, two articles (2.9%) had a qualitative design, and two articles (2.9%) were case reports. Regarding the geographical distribution of production, 41 articles (58.6%) were conducted in North America, and 22 articles (31.4%) were elaborated in Europe, totaling 63 articles or (90.0%) of the selected ones. Five other articles (7.1%) were from Asia, one article (1.4%) from Africa, and one article (1.4%) from Oceania. There were no research articles from Latin America and the Caribbean.

The articles addressed various aspects related to the perpetrator of sexual homicide using different analysis tools and models in heterogeneous populations, which limited comparisons. In 52 articles (74.3%), there was a predominance of study variables related to psychiatric, behavioral, or psychological disorders of the sexual homicide perpetrator, emphasizing sadism, as well as paraphilias, forms of sexual violence, and methods employed for the lethal outcome. One or more identified themes were grouped according to table 1, indicating their authorship and the reference of the articles in which they were addressed.

The synthesis of the main findings from the 70 selected original articles is presented in table 2 in chronological order, indicating authors, year of publication, journal, and study characteristics.

DISCUSSION

Out of the 70 selected articles, only one study reported a decline in sexual homicides. The analysis of Myers et al.⁵⁴, from 1976 to 2007, there was a decrease in this crime in the USA committed by young and adult men, along with a significant increase in the average age of the perpetrator from 25 to 29 years. Some descriptive studies provided sociodemographic information about the perpetrator. In China, data from 59 sexual homicides collected from case reports and police databases between 1994 and 2016 showed that the perpetrators had an average age of 32.4 years, 97% were men, 67% were single, 68% had completed high school, and 80% had no previous criminal convictions⁷. In Canada, a study of 250 solved sexual homicides between 1948 and 2010 found an average age of the perpetrator at 28.4 years, with 66% being Caucasian and 57.2% being single⁸.

Sexual homicides of adult women seem to be more associated with indicators of instrumentality and individuals with sexual deviances more frequently⁷³. Myers et al.19 studied incarcerated young sexual homicides in the USA. All victims were women of the same race and residing in the same area, experiencing vaginal acts in over half of the cases. Weapons were used in almost all cases. Thirteen young perpetrators had a history of violence, and twelve had been previously arrested before the sexual homicide. Chaotic, abusive contexts, and low school adaptation were common events, with conduct disorder present in twelve youths and violent sexual fantasies reported in half of the sample. In later studies, Myers and Monaco³² and Myers and Blashfield³¹ did not identify that sexual homicides committed by young individuals were motivated by anger.

Young sexual homicide perpetrators were addressed in the article by Myers and Blashfield³¹. Moderately high scores of personality disorders and psychopathy were found in 14 studied cases, with two-thirds of young sexual homicide perpetrators reporting violent sexual fantasies. The majority of these offenders used knives to kill known victims selected as low-risk.

On the other hand, only one article addressing elderly sexual homicide perpetrators was found. In the EUA, Myers et al.⁶ compared 3,453 cases of sexual homicide with an age range starting at 55 years using data from US Supplementary Homicide Reports. The authors identified 32 elderly sexual homicide perpetrators, comprising 0.5% of the sample, highlighting a preference for older female victims. Similarly, only one article compared characteristics of male sexual homicide perpetrators from two countries⁶⁴.

Serial sexual homicide was found in some articles. Myers et al.⁴⁴, in a study with 22 young men who committed sexual homicide, found a high prevalence of conduct disorders, personality disorders, and sexual sadism. Recidivism occurred in 55% of cases among offenders with higher scores on the Hare Psychopathy Checklist-Revised, with 27% of them escalating to serial sexual homicide.

Schlesinger et al.⁴⁵ assessed a national sample in the USA consisting of 38 serial sexual homicide perpetrators and 162 victims regarding the possibility of engaging in rituals or leaving any “signature” in the crimes. The findings did not support these hypotheses, suggesting that the conduct of serial killers at the crime scene appeared to be complex and heterogeneous.

Some studies indicated that serial sexual homicide perpetrators, although considered methodical, took a substantial amount of time between crimes to avoid being identified, much like organized behaviors of non-serial sexual homicide perpetrators seem to do to delay crime detection⁵⁵. However, this information was contested in the study by Schlesinger et al.⁵⁸, when analyzing a non-random national sample of 44 serial sexual homicide perpetrators and 201 victims. The authors found that 56.8% of sexual homicides had intervals of more than 14 days between crimes, 43.2% were committed within less than 14 days, and 13.6% occurred in rapid succession with few days in between.

In the article by Sewall et al.⁴⁹ a model was tested that classified serial sexual homicide into three types of offenders based on biographical data from 82 individuals, considering that other typologies lacked theoretical foundation and empirical support. The analysis produced five components composed of offender and crime characteristics, and the cluster analysis revealed three distinct groups of perpetrators: sadistic offenders, competitively disadvantaged offenders, and slashers.

Healey et al.⁵³ explored the sexual killer as a unique type of offender hypothesis and sexual homicide as a distinct outcome from the sexual violence hypothesis. When it comes to young male sexual homicide perpetrators, Chopin and Beauregard⁷⁰, identified patterns of offenders characterized as explosive opportunist, sadistic, super-controlled anger, and predator.

Research focusing on the possible effect of adverse childhood experiences on men who have committed sexual homicide is considered scarce, although theoretical models have postulated their association with the development of internal risk factors in the offender⁷⁰. However, some articles addressing this aspect were found. In the United Kingdom, Milsom et al.³⁴ conducted a qualitative study comparing levels of emotional loneliness between sexual homicide perpetrators and non-lethal rapists, employing the inductive-deductive method of Grounded Theory. Sexual homicide perpetrators reported higher levels of complaints regarding women in childhood and loneliness during adolescence.

In Canada, a study by DeLisi and Beauregard⁶⁰employed the framework of adverse childhood experiences to assess associations between exposure to violence, victimization, and total adverse childhood experiences within a sample of 85 men convicted of sexual homicide. The likelihood of committing sexual homicide increased by 334% when the offender had a history of childhood violence, by 249% when they were victims themselves, and by 546% with the total adverse childhood experiences. These effects intensified in adjusted models for childhood enuresis, animal cruelty, parental abandonment, deviant sexual behavior, self-image issues, and sexual disorders.

In Canada, Firestone et al.²³ compared 48 sexual homicide perpetrators with incest perpetrators, using the Derogatis Sexual Functioning Inventory, Buss-Durkee Hostility Inventory and the Psychopathy Checklist-Revised (PCL-R). Sexual homicide perpetrators reported a more frequent occurrence of being removed from their homes during childhood and experiencing more violent experiences. In Finland, a history of childhood sexual abuse was also reported more frequently among sexual homicide perpetrators¹³.

Few articles reported aspects of the physical health of sexual homicide perpetrators. In Germany, Rettenberger et al.²⁷ investigated 163 sexual homicide perpetrators and found a significantly higher occurrence of genital abnormalities in childhood (cryptorchidism, hypospadias, and phimosis) compared to the general population. They also found a higher frequency of sexual dysfunction in adulthood and a greater tendency towards masochistic sexual interests.

The article by Briken et al.³⁷ described the identification of XYY karyotype, Jacob’s Syndrome, in three sexual homicide perpetrators. The prevalence was 1.8%, significantly higher than that found in unselected samples of convicts (0.7% to 0.9%) and in the general population (0.01%). The three men had prepubertal abnormalities, school problems, suffered physical abuse, and were diagnosed as sexual sadists.

Neurochemical and neuroimaging studies indicate the involvement of morphological lesions and functional deficits in certain brain centers as part of violent behaviors, primarily the limbic system, temporal lobes, and frontal lobes²⁶. However, none of the articles selected in this review conducted research in this field, emphasizing instead clinical studies on psychiatric and behavioral disorders related to sexual homicide.

In Australia, Kocsis et al.¹⁴ examined 85 cases of sexual homicide sampled from all jurisdictions of the country using a multidimensional scaling statistical procedure. The authors identified four distinct offender patterns: predator, fury, perversion, and rape. Each pattern presented a distinct crime dynamic and style.

Several articles addressed sexual sadism as an important element in sexual homicide. Rajan et al.⁶⁵, in Scotland, found psychopathy and sexual sadism playing pivotal roles, interacting with each other and determining different aspects of sexual homicide and the offenders. Stefanska et al.^9, using the Sexual Sadism Scale (SeSaS), found a prevalence of 37% of sadism in a national sample of 350 men who committed sexual homicide in England and Wales against adult women. Hill et al.³⁶ compared characteristics of 61 sadistic sexual offenders and 105 non-sadistic ones, finding a higher history of childhood nocturnal enuresis, isolation, signs of Attention-Deficit/Hyperactivity Disorder, physical abuse, and recurrent lying among sadistic offenders.

Porter et al.^1,18psychopathic and 20 non-psychopathic sex killers coded by the PCL-R were analyzed. The majority of sexual offenders (84.7%) scored in the moderate to high range on the PCL-R, and in 82.4% of cases involving psychopaths, some degree of sadistic behavior in the crime was found. Sexual sadism was also associated with various aspects at the homicide scene, allowing the distinction between the two groups³⁸. In Rodre et al.⁶⁸ article higher PCL-R scores were also described in individuals convicted of sexual homicide.

In the article by Hill et al.²⁵, the presence of sexual psychiatric disorders was compared between 130 single-victim sexual murderers and 36 with multiple victims, using psychiatric reports and the Criteria from the Structured Clinical Interview and PCL-R instruments. In the multiple sexual homicide group, there was a higher frequency of sexual sadism, voyeurism, and sadistic, antisocial, and schizoid personality disorders.

In Beauregard and DeLise⁷²article, comparing sexual murderers with non-homicidal sexual offenders found that murderers had a higher frequency of Schizoid and Borderline Personality Disorders. Additionally, they were significantly more likely to select victims, use weapons, and use illicit drugs and alcohol before the crime. A similar study by Langevin²⁴ comparing these two groups found that sexual murderers initiated crimes earlier, joined criminal groups, engaged in cruelty to animals, and showed a higher frequency of sadism, fetishism, voyeurism, collection of pornography, antisocial personality disorder, neuropsychological impairment, and learning difficulties.

The motivation of sexual murderers for the crime has been explored in some articles, mostly conducted in China. Those who mutilated victims were found to be more motivated by sex than financial gain and more likely to have a previous conviction for sexual crime, according to Chan and Li⁶². Offenders motivated by sex, money, and anger were more likely to target unknown women, while those motivated by power and control were more likely to target partners, as per Chan et al.⁶⁷. Sexual homicides against women based on sex were verified by Chan and Li⁷¹.

Canadian sexual murderers and non-homicidal offenders were studied in an article by Chan and Beauregard¹⁸. Sexual murderers often selected and mutilated victims, had more deviant sexual fantasies, and admitted to the crime more easily when identified and arrested. They exhibited more paranoid, schizotypal, borderline, histrionic, narcissistic, obsessive-compulsive, and impulsive personality traits. They were frequently involved in exhibitionism, fetishism, frotteurism, homosexual pedophilia, and sexual masochism.

In the United Kingdom, Stefanska et al.⁷⁶ also addressed deviant fantasies in non-serial sexual murderers, comparing whether the sexual element and the act of killing were directly or indirectly associated and the level of injuries, according to the Homicide Injury Scale (HIS). Although no difference in mean scores was found, there was a direct association between the sexual element and the crime.

Similar themes were found in Koch et al.²² article, which compared the prevalence of psychiatric disorders in 166 sexual murderers and 56 non-murderers, using the Structured Clinical Interview for DSM Axis II Disorders (SCID-II) and PCL-R instruments. Sexual murderers were more frequently diagnosed with personality disorder (80.1% versus 50%), schizoid personality (16.3% versus 5.4%), sexual sadism (36.7% versus 8.9%), and sexual dysfunctions (21.7% versus 7.1%).

Partially, these findings also emerged in serial crimes. In Chan et al.⁵⁰ article, 73 single-victim sexual murderers were compared to 13 serial sexual murderers. Serial murderers were more likely to report deviant sexual fantasies, select and humiliate victims, and premeditate the crime. They showed more narcissistic, schizoid, and obsessive-compulsive traits, as well as sexual masochism, homosexual pedophilia, exhibitionism, and voyeurism.

Other articles with different study populations were found. In the US, Gacono et al.³³ analyzed 32 non-sexual aggressive psychopaths with 38 sexual murderers and 39 non-violent pedophiles on selected variables from the Rorschach test. Sexual murderers showed high levels of obsessive thinking and an inability to disengage from environmental stimuli. Huprich et al.³⁵ applied the Rorschach Oral Dependency Scale to 32 non-sexual aggressive psychopaths, 38 sexual murderers, and 39 pedophiles. The authors found a high degree of association between interpersonal dependency and aggression among sexual murderers. In Healey et al.⁴⁸ article, it was suggested that several behaviors at the crime scene overlap with the diagnosis of sexual sadism, capable of distinguishing between sexual offenders against women and sexual murderers.

Kerr and Beech⁵¹ published one of the few qualitative articles we identified, analyzing eight individuals convicted of sexual homicide in the United Kingdom. The authors identified four significant themes to understand sexual homicide, attributed to revenge, psychic disorder, homicidal impulse, and emotional loneliness.

Two articles addressed the investigation and resolution of sexual homicides. In Sweden, Sturup et al.⁶¹found similar percentages of solved sexual homicides (82%) and non-sexual homicides but noted that cases with a sexual component took longer to be resolved. In Canada, Chai et al.¹⁶ investigated patterns of victim body disposal in sexual homicides. In solved cases, the bodies were moved when the victim was a sex worker, and the body was hidden and in the prone position. In unsolved cases, body movement occurred when the victim was a sex worker, and the body was recovered outdoors.

Noteworthy articles focused on the victim-offender relationship. Oliver et al.³⁹ compared 58 sexual murderers and 112 sexual offenders. Sexual murderers were less likely to have relationships at the time of the crime and tended to select older victims. However, the authors found no differences in the Millon Clinical Multiaxial Inventory-III personality scales. Abrahams et al.³ found that the offender was more likely not to know the victim, who was generally older than the offender.

The gender issue was addressed in Chopin and Beauregard²⁹ article, comparing 100 male victims and 552 female victims of sexual homicide. According to the authors, gender played a significant role in offenders’ behaviors, adapting strategies to overcome the risk of physical confrontation with male victims. In female victims, physical violence and resistance to the offender were strongly associated with sexual homicide⁶³.

The choice of the victim also involved a specific situation in an article. Morrison⁴⁰ presented a case report of workplace stalking followed by sexual homicide of a woman with multiple sharp-blunt injuries. The author highlighted the stalker called predatory as distinct due to its dangerous nature and engagement in sexual violence.

An article addressing racial aspects in sexual homicide was identified. Chan et al.⁴⁶ examined the influence of race and age on the victim-offender relationship in a sample from the Supplemental Homicide Reports, with data from 1976 to 2005. White sexual murderers were highly prone to killing people of the same race, while black offenders killed both black and white individuals.

The articles pointed out significant heterogeneity among sexual homicide victims, as well as the sexual acts committed and the lethal outcomes involved. Only one article dealt with multiple offenders and more than one simultaneous victim¹⁰. Chan⁷ and Chan et al.⁶⁶ articles pointed to the mutilation of the victim’s body and acts involving vaginal penetration. According to Beauregard and Martineau⁸, vaginal intercourse occurred in 46.3% of sexual homicides, and anal intercourse in 16.3%. The victims were predominantly women (89.7%), white (62.8%), and with an average age of 27.2 years. Sexual homicide mainly occurred through beating (47.1%) and strangulation (41.7%). Similar results were found in Abrahams et al.³ article, with sexual homicide victims having a higher number of injuries and lethal outcomes due to strangulation or blunt trauma.

In the United Kingdom, Carter et al.⁵⁷ compared the crime scene in sexual and non-sexual homicides, finding that sexual crime victims were more frequently found at home, with the lower half of the body exposed, evidence of vaginal sexual acts, and extreme injuries and strangulation. Regarding post-mortem sexual acts, Higgs et al.⁵⁹ found no higher use of weapons or unknown victims in sexual homicides. In these cases, Chopin et al.⁷⁵ suggested four patterns of necrophilia in sexual homicide: preferential, opportunistic, experimental, and sadistic. Only preferential offenders killed victims to have sex with the corpses, while in other offenders, necrophilia was part of a deviant and secondary process.

Some articles also presented studies associating sexual homicide with paraphilic disorders. Piquerism was described by Pettigrew²¹ in a case where the offender used multiple stabbings for the sexual homicide of five male victims. A Canadian study by Beauregard et al.⁷⁷ with 662 sexual homicide cases compared the insertion of foreign objects into the victim’s mouth, anus, or vagina with sexual homicides without insertion. In 84 cases (12.7%), foreign objects were inserted into the victim’s body, more common when the offender had sexual dysfunction, sadism, when victims used alcohol or drugs before the crime, and when they were beaten. Post-mortem sexual acts and strategies to hinder the identification of the offender were more likely in cases of object insertion.

In the US, Koeppel et al.¹¹ compared a non-random national sample of 207 non-serial sexual homicides and 53 serial homicides, finding object insertion in 50 cases (19.2%), with a similar distribution in both groups and similar levels of sadism.

Although a significant portion of sexual homicides involves the use of weapons⁶⁷, the articles revealed that sexual murderers showed a preference for strangulation, asphyxiation, or beating^8,12. An exceptional situation was described only by Myers et al.⁴², with five cases of sexual homicide resulting from autoerotic asphyxiation, four in the US and one in Russia, all associated with the offender’s sexual sadism. Only one article focused on the movement of the sexual murderer, suggesting that those involved in long routes tend to target sex workers and move the body after the crime, according to Martineau and Beauregard56. Information on sexual homicides of female sex workers was presented by Chan⁷⁴.

A relevant number of articles were found on the recurrence of sexual homicide. In Germany, Hill et al.⁴¹assessed 90 sexual murderers through Kaplan-Meier analysis, finding a 23.1% risk of violent sexual reoffending and an 18.3% risk of violent non-sexual reoffending. Violent reoffending was associated with the offender’s young age at the first sexual crime.

In another study, Hill et al.⁴⁷ retrospectively examined the predictive accuracy of the PCL-R, Assessing Risk for Violence-20 (HCR-20), Sexual Violence Risk-20 (SVR-20), and Static-99, based on psychiatric reports. Like in other studies, total scores and subscales of the instruments were unable to predict sexual homicide reoffending^36,41,47. According to Busch et al.⁴³, low social maturity and previous convictions were predictors of reoffending risk. The article by Khachatryan et al.⁵²on adolescent sexual murderers observed that the average sentence duration was 12 years and 2 months. After 30 years of conviction, half of them were reconvicted for non-homicide crimes. Chopin et al.⁷⁸ reinforced that adverse childhood factors constitute a risk for sexual homicide.

Chopin and Beauregard⁶⁹ article reinforces that sexual murderers present significant differences when compared to other murderers or non-homicidal violent sexual offenders, suggesting them to be a specific type of offender. The authors found that sexual murderers were more likely to have paraphilic disorders and sexual dysfunction, more engaged in social activities, and less likely to use psychoactive substances and engage in criminal activities. In the modus operandi, the unknown and surprised victim or victims approached through fraud were more frequent. Sexual murderers committed the crime more often in residences or entertainment venues. The weapons used were less likely to be removed from the crime scene and more likely to be recovered by the police.

We believe that a gender perspective should be incorporated into the study of sexual homicides, as a significant portion of cases involves female victims. According to Lucena and Tristán-Cheever⁷⁹, gender inequality has roots in colonialist patriarchy mixed with racism. In fact, a study by Monteiro et al.⁸⁰indicates that femicide rates are higher among black women, although it is not possible to know how many of these deaths have sexual motivations.

CONCLUSION

Sexual homicides are less frequent lethal crimes. Male sexual offenders have shown to be a heterogeneous group, yet with various characteristics that differentiate them from other murderers, pedophiles, and sexual offenders. These perpetrators appear to target their crimes towards a heterogeneous group of adult victims, with particularities in the forms of lethal outcomes and the sexual acts committed. There is a high prevalence of psychiatric issues, behavioral disorders, and traumatic experiences during childhood within this group of homicide perpetrators.