A few serial killers act in pairs, each bringing a disturbed upbringing. Some report distress through lack of sexual opportunity. Attachments to others, engagements and commitments to work can offer some protection against following this toxic trajectory. The choice of victim reflects the killer’s sexual orientation and desirability of the target, and in some cases the perception of the victim’s guilt. Sex workers are the favoured victims, apparently reflecting the ease of access to them and their perceived immorality. Lust killing became most evident in the last quarter of the nineteenth century. In the twentieth century it became disproportionately an American phenomenon, with a peak in the 1960-1980 period.It can be speculated that various factors contributed to this rise, such as breakup of the traditional family structure, the availability of cars and highways and an increased frequency of drug addiction amongst sex workers. Lust killers are almost without exception male.

People are susceptible to boredom and seek an optimal level of arousal. Psychopathic individuals appear to be low on arousal, and they try to elevate this by seeking novelty and taking risks. Ways to achieve the optimal level by sensation-seeking include transgressions such as violence, arson and theft. These can have sexual associations and are sometimes accompanied by masturbation. Dopamine activation is at the basis of elevations in arousal. Serial lust killers commonly have a history of committing non-sexual crimes and arson. The internal organs of the body are under the control of the autonomic nervous system, high arousal being associated with dominance of the sympathetic branch and low arousal with the parasympathetic branch. Arousal is largely non-specific, and it takes a positive or negative value according to context. Switches can be made from negative to positive, which appears to lie at the basis of some lust killing.

Some cases of sexual serial killing exemplify anger directed at an ex-wife/partner, which gets transferred to other women. These involve (1) displaced aggression and (2) collective guilt of women as a whole, or particular types of women, such as sex workers. Faryion Wardrip exemplifies anger directed towards his ex-wife, and he reported seeing her face as he was killing. The killings appeared to be unplanned. Russian police officer Mikhail Popkov discovered his wife had committed adultery. Dividing women into saints and sinners, his discovery triggered a campaign of raping and then killing those he considered to be immoral. He would offer women lifts in his car and invite them for a drink. If they gave an answer of the kind 'Sorry but I must get home', they were spared, even escorted to their front doors. If they answered 'yes', this was a death sentence - an example of ‘mission killing’.

Serial killers tend to score highly on a scale of psychopathy, ticking boxes such as low empathy and glib superficial charm. Another condition that can be tapped to derive insights is anti-social personality disorder (APD). Some reports of the experiences of lust killers point to a split in individual consciousness, sometimes expressed as good versus bad personalities. There can be a sudden flip between these states. This is sometimes conceptualized as dissociation and can be revealed as ‘voices in the head’. It is distinct from psychosis and has not been successful as a plea for mitigation. Characteristics of dissociation include viewing oneself from a distance, having a poor or no memory of the killing (i.e. memory specific to the state at the time of the killing) or seeing a disliked person as the target of the attack. Some serial killers are diagnosed as psychotic.

For some, part of the attraction of lust killing is the opportunity to pose wearing the clothes of their victims. For the two discussed here, this would seem to be a dominant paraphilia. Both men showed evidence suggesting a role of stress in their killing. Commander of the largest military base in Canada, Colonel Russell Williams would seem to be a most unlikely sexual serial killer, particularly since his victims were women under his command. Williams graduated to killing via breaking into homes and stealing pairs of underwear. He built an enormous collection of these, all carefully curated. It is possible that the drug Prednisone played a role in his aberrant trajectory. Dennis Rader appeared similarly to be a respectable family man. There were several early experiences that he recalled (e.g. seeing his mother trapped) which might have played a role in his development.

Ted Bundy was separated from any individual caregiver after birth. Apparently, he was disturbed by the uncertainty around who was his biological mother. Pretense on who she really was might also have contributed to his distress. These experiences seemed to have initiated his resentment against women, which were subsequently inflamed by jilting. Intelligent, handsome and articulate, Bundy was described as a most unlikely serial killer, which shows the limitations of stereotypes. He was very sensitive to social class and uncomfortable with his own position. He illustrates a feature of displaced aggression: that retribution can be out of all proportion to the initial trigger. Bundy was an organized offender committing murder in a series of states of the Union. However, he became somewhat disorganized at the end of his killing series. Bundy exemplifies the use of cognitive empathy to gain access to his victims. He claimed that violent pornography played a role.

A paraphilia is sexual behaviour that lies outside conventional bounds, such as exhibitionism. They are of interest in that lust killers commonly also exhibit paraphilias, and they can form an association with killing. Voyeurism sometimes features in association with lust killing, as a gateway activity. A fetish describes sexual arousal to an inanimate object, while a partialism describes sexual arousal to particular body features, such as feet. Serial lust killers often take objects (such as items of clothing) from their victims, in an attempt to recreate the killing, accompanied by masturbation. Sometimes a body part is taken, such as a breast. The term ‘picquerism’ refers to sexual arousal derived from cutting the skin. There are some features in common between non-lethal rape and lust killing. Rape sometimes serves as a gateway activity for lust killing. Some men are attracted to necrophilia without showing violence towards their target.

Some sexual killers choose victims in a particular age group. Three killers described here (Igor Irtyshov, Clifford Olson and Arthur Bishop) preferentially targeted children and young adults. Olson was an all-round career criminal who showed bisexual tendencies. Vladimir Vinnichevsky killed very young children, while Anatoly Biryukov sexually attacked and killed babies. Vasily Kulik tortured cats, and later showed a preference for killing children. His switch from young adults to children and elderly women followed damage to his head, which could have harmed his brain. Bishop gave an account of craving, ambivalence, escalation and fighting temptation. He illustrated the difficulty of trying to resist intrusive thoughts (something that psychologists call the ‘white bears effect’). For Irtyshov, the form of rape and choice of victim reflects the assaults that were earlier inflicted upon him.

Insights into killing can be obtained by considering theories of general crime and non-lethal sexual offending. This chapter considers the theoretical positions of Marshall, Barbaree, Malamuth, Ressler et al. and Seto. Drive theory fails to explain behaviour and has largely been replaced by incentive motivation theory. The distinction between organized and disorganized lust killers is not an absolute one but represents two extremes on a continuum. By sensory preconditioning, two events that occur together can become associated, such as sexual desire becomes paired with an aversive emotion. Even though killing appears to be maladaptive, evolutionary approaches can still give insights. The theory of Belsky et al. suggests that uncertainty of social support during development is assimilated and plays a role in determining reproductive strategy. An evolutionary argument suggests that male serial killers reflect a hunter/stalking strategy, whereas female serial killers reflect a strategy of staying at home and maximizing genetic benefit.

The chapter considers the range of features that enable investigators to describe a killing as ‘sexual’, such as clothes removed, objects inserted into the body and presence of seminal fluids on the body. Some killing done in association with sexual behaviour is not motivated by lust. For example, it might represent an attempt to avoid capture following a sexual assault or the accidental result of choking. Some killers reach orgasm from simply cutting a victim, while others (e.g. David Berkowitz) are sexually aroused by shooting a courting couple. The chapter describes a number of common features of a ‘composite killer’, such as cruelty to animals and voyeurism. Various ruses might be used in order to get a victim in the situation where he or she can be killed, such as offering a lift or seeking help. However, the most common method appears to be to engage the services of a sex worker.

Bowlby proposed that the child forms a working model of the relationship between his/herself and caregivers. Where there is abuse, the working model represents this. In response, the child can learn to perform aggressive behaviour. A common feature of serial lust killers is that they experienced humiliation in their early lives. Early sources of abuse include physical, psychological and sexual. Later sources of trauma include taunting over sexual orientation and failure to find a girlfriend. Somewhat similar to the notion of ‘working model’ is that of a ‘love map’. The love map can be corrupted so that violence becomes encoded. The process of sensory preconditioning is under the control of dopamine and is responsible for forming links between an aversive emotion and sexual desire. In some cases, a traumatic memory can be revised to take on positive qualities and underlie lust killing. The Old Brain matures faster than the New Brain.

Some serial lust killers suffer from erectile dysfunction in the context of a consensual relationship with a living human. In one sample of them, 44 per cent indicated erectile difficulties. It appears that some killers can only secure and maintain an erection, if at all, in the presence of a dead body, as with John Christie, or blood, as with Andrei Chikatilo. More speculatively, Robert Lee Yates Jr. also fits this description. It appears that John Christie was mocked for erectile difficulties. He viewed the body of his grandfather, which possibly had a role in the tragedy. It is possible that being gassed in World War I contributed to his pathological sexuality. Andrei Chikatilo is the most famous serial killer from the USSR. His early life in the Ukraine was associated with a multitude of different stressors. His erectile difficulties might have stemmed in part from bullying and taunting.

Sometimes killing by male-female couples represents an escalation of an adventure that starts with entirely, or at least relatively, harmless activities, as in looking at fringe pornography, sharing fantasies or accounts of earlier experiences, S&M or swinging. In some cases, this could be seen as grooming by the male. The existence of killer couples raises the issue of whether the female derives sexual pleasure from killing or the pleasure comes solely from pleasing the male . In each of the couples described here, the male would appear to be the dominant partner. For Ian Brady and Myra Hindley, it is unclear what set them on his tragic course. For Brady, it was possibly resentment against illegitimacy and social standing. Fred and Rosemary West both came from abusive backgrounds. The case of Paul Bernardo and Karla Homolka raised the issue of whether Homolka showed evidence of Stockholm Syndrome.

The chapter gives several examples of sexual serial killers who incorporated fetishes or partialisms into their killings. Glen Rogers was pushed under water by his red-headed mother. When killing, he targeted red-headed women and their bodies tended to be left in water. Volker Eckert had a fetish linked to women’s hair, and the assaulting of women while touching their hair formed a gateway activity to killing. Jerry Brudos developed a shoe fetish after being punished by his mother for wearing women’s high-heel shoes. This exemplifies high incentive salience being attributed to shoes. Salience then extended to women’s feet, a partialism. Charles Albright developed a fetish for eyes, having had early experience with eyes in the course of taxidermy. Yuri Tsiuman obtained an orgasm while choking a woman wearing black tights. Subsequently, he targeted women wearing black tights. H. H. Holmes shows some characteristics of having a fetish acquired to a skeleton.

We know a lot about Jack the Ripper’s crimes, but have no idea as to who he was. His crimes had a sexual character, and his dislike of women could be because he caught venereal disease from one. He targeted, amongst other regions, the women’s sex organs. We don’t know the identity of the Zodiac Killer, who targeted courting couples. It is likely that he felt envy towards them. Although Albert DeSalvo was widely believed to be the ‘Boston Strangler’, not everyone is in agreement about this and he was not found guilty of these crimes. However, his toxic upbringing and his characteristics of offending fit the pattern of other known serial killers. He showed evidence of dissociation. DNA evidence points to his involvement in at least one of the murders. A perspective of motivation might cast some light on these cases.

Sometimes two males combine their efforts in the sexual killing of women. Each brings a damaged history and personality. The combination then shows such additional features as male bravado, bonding and loyalty. In the best-known cases, one of the pair is the junior partner and the other the senior. This chapter looks at the lives of two such pairs: (1) Leonard Lake and Charles Ng and (2) the so-called Hillside Stranglers, Angelo Buono and Kenneth Bianchi. Leonard Lake was disturbed by being abandoned by his mother. Charles Ng was subject to harsh discipline. Lake, who exhibited murderous sibling rivalry, formed the senior partner of the two. They aimed to collect a population of sex slaves. Angelo Buono and Kenneth Bianchi both had disturbed backgrounds, Buono being the senior partner of the two. Bianchi was shunted around before being adopted. They sexually abused and tortured women before killing them.

Revenge probably features in most, if not all, lust killing. This chapter exemplifies where revenge for perceived transgression comes into the clearest focus and seems to occupy center stage. Of course, the revenge was disproportionate to the ‘offence’, a feature of displaced aggression and ‘revenge collecting’. Part of the trigger to revenge is a blow to self-esteem. The antagonism that Peter Sutcliffe felt towards women appeared to derive from suspicions over his partner’s infidelity and being cheated by a sex worker. Sutcliffe seemed to have a kind of love-hate relationship with sex workers. He was fascinated by them and engaged them in sex but was alsodisgusted by them and killed them. It can be speculated that Levi Bellfield’s toxic trajectory started when as a boy he was jilted by a blond girl. Most of his victims were blond girls, yet he sought this type as his girlfriends. Sergey Golovkin targeted boys.