Most people get their impressions about serial killers from movies and T.V. shows such as Criminal Minds and C.S.I shows, but in reality, there is a lot more that people don’t know. They usually picture a while male in his mid-20s but there is no such thing as a stereotypical serial killer (Reid, 2017). They are the hardest to predict due to their rare occurrence compared to other crimes. Researchers have estimated that there are at least 300 serial killers in the United States alone (Johnson & Becker, 1997). A serial killer is traditionally described as a person who has murdered three or more people separately with a period of inactivity between killings (Holmes & Holmes, 2010; as cited in Alley, Minnis, Thompson, Wilson & Gillberg, 2014). Forensic Psychiatrist Park Dietz (1993; as cited in Johnson & Becker, 1997) identified five different categories of serial killers: psychopathic sexual sadists, crime spree killers, organized crime, poisoners (doctors who kill) and psychotic. Psychologists continue to study whether serial killers are predisposed to these inclinations, or if these urges appear suddenly with no prior warning. The subsequent research is an exploration of the case study analysis on genetic and psychosocial factors that contribute to the development of serial killers. My hypothesis is that the making of a serial killer starts years before due to the combination of genetic and psychosocial factors.
Supporting Evidence
Genetic Factors
The first study of genetic factors on serial killers started in the nineteenth-century. In 1857, Bénédicti Augustin Morel was the first to argue a theory called degeneration. Although later disproved, said that major mental illnesses have a genetic and biological component, and stated that they get worse as they are passed down many generations, ultimately explaining the reasoning behind the increase in violent criminals. Around the same time, Cesare Lombroso, a prison physician, was the first to do neurological examinations on a serial killer. He examined criminals’ facial features to determine if they are a murderer or not (Reid, 2017) but this theory was also later disproven. The twentieth and twenty-first century biological experiments were able to determine more about the genetic factors that are apparent in individuals who are serial killers.
One genetic factor that is collectively found in serial killers is neurochemical imbalance. Low serotonin (5-HT) levels are seen to cause impulsivity, self-destruction violent tendencies and aggression in humans (Alley et al., 2014). British psychologist Adrian Rain (1993; as cited in Alley et al., 2014) noted that the lack of dopamine and norepinephrine also generally cause aggression. Lower levels of monoamine Oxidase A (MOA – A), an enzyme primarily involved in the catabolism of serotonin is also another imbalance that is linked to aggressiveness in humans (Reid, 2017). Higher levels of testosterone are linked with stronger stages of aggression, which would make sense, considering men mostly consist of the serial killer population.
Another factor that is seen occasionally in serial killers is serious illnesses in fetal/early childhood. According to Michael Stone, professor of clinical psychiatry at the Columbia College of Physicians and Surgeons (2009; as cited in Reid, 2017), meningitis is commonly found in the serial killer population. Meningitis is an inflammation of the membranes that surround the brain and spinal cord. Fetal toxin exposure is also linked with having long-term effects on child development. More generally, research from Harvard showed that cities with higher homicide rates were the cities that made use of lead service pipes (Feigenbaym & Muller, 2016; as cited in Reid, 2017). Lastly, birth complications, such as anoxia, which is the absence of oxygen, can be a factor in the etiology of serial killers.
The most prevalent genetic factor that is linked between most serial killers is Autism Spectrum Disorder (ASD). Within the serial killer population, Alley et al. (2014) found that 10% of said individuals had evidence of Autism Spectrum Disorder. The high number of individuals that commit serial homicides and have ASD are said to do this because of the fact they are more a vulnerable population. Their vulnerability leads them to be more willing to commit these heinous crimes because they do not realize the acts they are doing are fatal or wrong. Most criminals diagnosed with Autism Spectrum Disorder are said to also have psychosocial factors acting in unison, such as neglect and abuse (Reid, 2017).
One influential case analysis done on the connection between ASD and criminal behavior was by Faccini and Alley (2016). They looked at the 1994 shooting spree of Dean Allen Mellberg at the Fairfield Air Force Base. Mellberg enlisted in the Air Force in 1992 and initially filled out his one medical form stating that he attended counseling for a mental condition. He started to exhibit odd behaviors such as low self-esteem, nervousness and excessive sweating when he was in basic training at Lackland Air Force. The first verbal complaint about Mellberg came in late summer 1992 from his roommate in which his roommate stated Mellberg would openly masturbate in front of him. After the initial complaint, his roommate mentioned that Mellberg threatened to set [the roommate’s] bed on fire, would often stare blankly at the wall for hours and often mentioned how he liked killing things. Mellberg would deny these claims and state that his roommate was trying to sabotage his career. Mellberg received the diagnosis of personality disorder with strong obsessive-compulsive tendencies from Captain Alan London. London recommended he be discharged, but that did not happen. After multiple evaluations, Dr. John Campbell diagnosed him with autism, but due to a processing error, Mellberg ended up in Cannon Air Force in March of 1994. Two months later, another psychological evaluation was order and he was once again diagnosed with autism and paranoid personality disorder by Captain Lisa Snow. Due to his extensive knowledge of the layout of the base and security’s positioning, Mellberg did not need to do too much planning. He then purchased a MAK-90 with five rounds of ammunition and another 70-round cylinder. After leaving the bathroom of the Fairchild Medical Treatment Facility, Mellberg would end up killing four people and wounding at least 21 others. This case analysis showed the importance of taking the necessary precautions when dealing with an individual with a mental diagnosis in addition to grievances upon people.
In Alley et al. (2014) study, they peer reviewed literature about 239 killers. It showed that 28.03% had definite or was highly probable for having ASD. 55% of those having ASD also experienced psychosocial stressors. Alley et al. (2014) also did a case study of Jeffery Dahmer. Dahmer was a serial killer between 1978 and 1991 who murdered 17 men and boys. In addition to the murder, he also was found to do the following: rape, dismemberment, necrophilia and cannibalism, attempts to lobotomize. Silvia, Ferrari and Leong (2002; as cited in Alley et al., 2014) noted that Dahmer may have suffered from Asperger’s syndrome, which is a high-functioning form of Autism Spectrum Disorder. His social skills deficit explained his lack of bonding during childhood years and his inability to make friendships, essentially being labeled as a loner. His difficulty with nonverbal communication and unusual gaze were seen as odd and bizarre by Dahmer’s teacher, both which are common with individuals with ASD (Volkmar & Klin, 2000; as cited in Alley et al., 2014). Volkmar and Klin (2000; as cited in Alley et al., 2014) also noted that symptoms of Autism Spectrum Disorder are usually recognized at the age of three which is consistent with Dahmer’s father’s reports around the time Dahmer was four. Most persons with ASD repeatedly think about the same thing or do the same behaviors over and over again, which is found in Dahmer’s obsession with human bodies and also his flat monotone speech is another indicator of ASD (Masters, 1993; as cited in Alley et al., 2014). In addition to his ASD, Dahmer also had psychosocial stressors that could have caused frustration that later turned into his homicidal behaviors. This research suggested, as does the Mellberg case study, that not only are genetic factors influential, so are psychosocial factors.
Psychosocial Factors
As mentioned earlier, although there is some correlation between genetic influences and serial killers, most of the time there are psychosocial factors that also play an important responsibility. One case study done by Alley et al. (2014) looked at the serial killer Richard Ramirez, who was famously known as the night stalker. Ramirez was convicted of killing 13 people within the span of one year. During his lifetime, Ramirez sustained numerous head injuries and multiple psychosocial stressors. His family played a big factor in his exposure to violence. Both of his parents were exposed to nuclear radiation and his mother mixed toxic chemicals for hours at a time as a job and as a result, he collapsed when she was five months pregnant with Ramirez. His great-grandfather and father were extremely physically abusive towards him and his cousin exposed him to sexual sadism, which is when one experiences sexual arousal in response to extreme pain, humiliation or suffering of others. When he was two, a dresser fell on his head, nearly killing him and three years late, he was knocked unconscious from a swing. At the age of 12, he saw a relative be murdered by another family member. In the fifth grade, Ramirez was diagnosed with epilepsy. Years later, he was diagnosed as having temporal lobe epilepsy. Common side effects from temporal lobe epilepsy is an altered sexuality and increased aggression. Ramirez’s case shows how the large influence of psychosocial factors can eventually leave one predetermined to commit an aggressive act.
Ressler, Burgess and Douglas (1988; as cited in Johnson & Becker, 1997) studied 36 murders who killed a total of 118 people and many of them had family histories of criminal, sexual, alcohol or drug abuse or psychiatric problems as well as some form of abuse. In Johnson and Becker (1997) experiment, they interview nine 14-18-year olds who fantasies about becoming a serial killer. These teens were either referred after committing a legal offense or a mental health worker noticed unusual behavior. Most of these teens were sexually active at a young age (some not by choice) and had multiple sexual partners. Six out of the nine teens grew up in an unstable family structure, including rape and abuse internally. Most of them were dependent on illegal substances and alcohol. Johnson and Becker (1997) found that these teens experienced these feelings due to their self-esteem being very low.
The most common psychosocial factors noted in serial killers is an aggressive sexual factor. Ressler et al (1988; as cited in Alley et al., 2014) declared that fantasy is the underlying basis for serial homicides, more specifically, sexual fantasies. Although these homicides tend to attract more public eye due to their extra dimension they add to murder, there are very little studies done on this fantasy. According to Hill, Habermann, Berner and Briken (2006), in order for a homicide to be considered sexual, it must meet at least one of the following conditions: attempted or completed any kind of sexual intercourse, exposure of the victim’s primary or secondary sexual parts, victim’s naked or almost naked, sexual positioning of the body, insertion of foreign objects intro the victim, semen on or near the victim, substitute sexual activity (ex. masturbation), the offender admitted there was a sexual interest and/or sadistic fantasies were admitted by the offender. Hill et al. (2006) found in their research, erectile disorders were in a fifth of their offenders they studied. Most commonly, they suffered from orgasmic disorder. As mentioned early in Johnson and Becker (1997) experiment, most of the teenagers interviewed experienced sexual gratification when thinking about killing something or when they physically killed something. One explanation for the increase in sexual need is that there are abnormalities in the temporal lobe (Gratzer & Bradford, 1995; Stermac & Hucker, 1988; as cited in Reid, 2017). This abnormality would cause an increase in poor impulse control, meaning the individuals are just physically unable to stop what they are doing.
Another common factor that puts people are a higher risk of violence, especially for serial murders is psychological disorders. According to research, individuals that are mentally ill are a higher risk of violence (Schanda et al., 2004; as cited in Culhane, Hilstad, Freng and Gray, 2011). Most sexual homicide offenders have been found with numerous disorders (Hill et al., 2006). Their research looked at psychiatric court reports on 166 men who committed a sexual homicide. The psychiatric disorders were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, edition 4 (DSM-IV) (Hill et al., 2006). The results showed that nine in 10 (90.4%) of the offenders showed at least one Axis I diagnosis (ex. ADHD, depression, anxiety), not including any disorders that were first diagnosed from birth through adolescence. 80.1% showed at least one personality disorder. But, although there is a high number of individuals in this study had psychiatric comorbidity, only 21.5% received treatment before their first sexual homicide.
A common psychology disorder found in individuals who commit homicides, especially serial killers is psychopathy. According to Hare et al. (1991; as cited in Reid, 2017), it comprises of around 1% of the general population. Psychopathy is when an individual lacks remorse and empathy. It is diagnosed with the Psychopathy Checklist – Revised (PCL-R) which is the most reliable measure for this disorder (Gacono, 2016; Sullivan, Abramowitz, & Kosson, 2006; as cited in Reid, 2017). Due to the lack of empathy, individuals with psychopathy are known to have an increased risk for criminality because they only care about what makes them satisfied and disregard the feelings of others. This would lead to them to doing whatever it takes, including harming others, to get their goal.
Discussion
Robert Morton (2005; as cited in Reid, 2017) defined the physical act of serial killing as the unlawful killing of more than two victims by the same offender at different times. Most of the time, the killings are premediated and planned. These murders are usually not in response to personal attacks or vendettas against anyone else.