The study results are of significant value for forensics; they were published in Psychology and Law journal.
According to experts, today, law enforcement officials often experience an acute shortage of scientific data on persons involved in serial sexual violence. MSUPE psychologists have developed a model that will make it possible to rely on reasonable assumptions about the typical personality features of offenders with specific search signs during the investigation.
The study was based on the ideas of Konysheva, a psychologist who divided serial sexual murderers into "sexual murderers", "force users" and "situational offenders" [Sitkovskaya & Konysheva, 2002]. The scientists have carried out an analysis that made it possible to isolate 39% of the "clean" type representatives; for the rest, the formation of criminal aggression is determined by a combination of "clean" type factors.
According to scientists, each type of criminal is characterised by a dominant personality feature. For "sexual murderers", it is a sexual pathology caused by organic brain disorders; for "force users" it is a borderline psychological pathology; and for "situational offenders" it is a deficit of personality structures (intellectual, emotional, social-role) controlling the implementation of aggressive and sexual drives.
"The work done allowed us to use the language of psychological determinants prevailing in criminal aggression formation instead of using descriptive metaphors when characterising serial sexual murderers' types", Nikolay Dvoryanchikov, Head of Legal Psychology Department at MSUPE, said.
The specific motivation of "sexual murderers" is determined by abnormal sexual drives, the satisfaction of which require killing the object of desire. The purpose of the murder is to achieve sexual arousal and orgasm from torturing the victim, or from the possibility of manipulating a dead body. Such killers are characterised by an active search for or the creation of a situation corresponding to their attractions.
The disharmony of personality traits among "force users" determines their desire for violent self-assertion. Sexual power and control, where killing is the victim's punishment, is associated with irreconcilable personal concepts of hostility towards women. Such criminals are extremely selective and careful about situational factors.
For "situational offenders", the murder is aimed at suppressing resistance and immobilising the victim to get access to their body. The mechanism of "redirecting aggression characterises such killers", that is, taking out their accumulated emotional negativity in relation to everyone in general and on their victim.
Situational factors clearly define such activity: the offender's actions are spontaneous and often associated with a high risk of detection, and the victim's resistance or eyewitnesses can lead them to interrupt what they've started.
"Statistical analysis revealed certain criminal behaviour markers specific to each of the three types of killers, as well as particular combinations of personality features with pre-criminal and criminal behaviour, specific to "force users" and "sexual murderers", Nikolai Dvoryanchikov said.
Sexual murderers' pre-criminal behaviour features include conflicts with spouses due to low sexual potency, lack of sexual attraction to women, unusual emotional attachment to children, adolescents and elderly people, as well as the desire to torture and kill animals. In addition, criminals of this type are characterised by late age of consent, endocrinological diseases and mental illnesses in close relatives.
According to scientists, the criminal activity of "sexual murderers" is characterised by choosing victims, both male and female, in a wide age range, which they often search for only in certain areas. They find the future crime scene in advance and are able to lure the victim by cunning.
Generally, criminals of this type murder the victim before any acts of a sexual nature, while some symbolic activity can replace sexual intercourse in a natural form. "Sexual murderers" tend to commit crimes before midday and steal low-value items from the victim.
"Force users" in their pre-criminal activity are prone to numerous sexual contacts and frequent partner changes; they like forcing partners into sexual intercourse, including through abusing their official position. Conflicts with spouses due to increased sexual demands and infidelity characterise them, the desire to hurt a partner and a fixation on caring about health, nutrition and physical fitness.
The victims of this type of killer are usually sexually attractive women between the ages of 18-25. The criminal studies and prepares the crime scene in advance. Sexual aggression, in this case, is not associated with deviation and involves sexual intercourse, most often multiple. A murder occurs only after a rape, and the victim's personal items are usually stolen for commercial gain.
The study used the archival data of Moscow and Moscow Region courts, as well as that of the Serbsky State Scientific Centre for Social and Forensic Psychiatry.