Cluster analysis of child homicide in South Korea

Child Abuse & Neglect 101 (2020) 104322

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Cluster analysis of child homicide in South Korea KyuHee Junga,b, Heesong Kima,*, Eunsaem Leec, Inseok Choia, Hyeyoung Limd, Bongwoo Leea, Byungha Choia, Junmo Kima, Hyejeong Kima, Hyeon-Gi Honga

T

a

National Forensic Service, Republic of Korea Department of Social Psychology, University of Tokyo, Japan Department of Psychiatry, Chung Ang University Hospital, Seoul, Republic of Korea d Department of Criminal Justice, University of Alabama at Birmingham, United States b c

ARTICLE INFO

ABSTRACT

Keywords: Child homicide South Korea Cluster analysis Gower distance Child abuse Homicide-suicide

Background: There has been an insufficient in-depth analysis of the nature and prevalence of the typologies of child homicide in Asia, particularly in South Korea. Objective: In the current study, we sought to determine the prevalence and identify the heterogeneity of the child homicide phenomenon in South Korea. Participant and settings: All 341 original case files (i.e., hospital, police, and autopsy reports) of homicide incidents involving children aged 0–18 in 2016 were obtained from the forensic autopsy archives of the National Forensic Service (NFS), which handles 100 % of the medico-legal autopsies in South Korea. These were examined and reclassified based on our definition. Method: A cluster analysis using Gower’s distance was applied, which has rarely been utilized in this field of research. By performing a qualitative analysis, we first extracted 70 (numerical, logical, categorical) crime, victim, perpetrator, and household relevant variables, which were later utilized in the cluster analysis. Results: Among the 341 cases from 2016, 95 were judged to be at least suspicious child homicide cases. When applying the cluster analysis, eight sub-clusters were extracted: child torture, maternal filicide, neonaticide, death not related to previous abuse, paternal filicide, paternal infanticide, maternal infanticide, and psychotic killings. Conclusions: The commonality and the unique aspect of the child homicide phenomenon in South Korea, in comparison with the results from previous research from other countries, are discussed.

1. Introduction Child homicide—the killing of a child by a person or persons (Alder & Polk, 2001) —has been prevalent throughout history and across cultures. Literature has postulated that qualitatively different subpopulations are involved in child homicide, and several researchers have sought to develop a typology that reflects the heterogeneity of child homicide (Lawrence, 2004; Roach & Bryant, 2015; Sidebotham, Bailey, Belderson, & Brandon, 2011). Indeed, the pattern and typology of child homicide are inevitably affected by the ever-changing culture of society. However, as most research on child homicide has been conducted in the Euro-American society, the nature, prevalence, and the typologies of this phenomenon in Asia are largely unknown, and there is a lack of in-depth analysis of child homicide in Asia (Hwa et al., 2015). Further, to the best of our knowledge, no study has examined the child homicide phenomenon in South Korea. In the current study, we not only seek to extrapolate the prevalence but also aim to identify the typology

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Corresponding author. E-mail address: [email protected] (H. Kim).

https://doi.org/10.1016/j.chiabu.2019.104322 Received 12 August 2019; Received in revised form 22 November 2019; Accepted 9 December 2019 0145-2134/ © 2019 Elsevier Ltd. All rights reserved.

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of child homicide in South Korea. To achieve this aim, child homicide cases were extracted from the forensic autopsy archives of the National Forensic Service (NFS) in South Korea, and person-centered techniques of cluster analysis (CA) were conducted using Gower distance. 1.1. Child homicide in South Korea Children, especially underage children, can die not only from fatal assaults but also by just “doing nothing” or by “negligent, neglectful” inaction (Scott, 2018). In such cases, since no external sign of injury is seen, post-mortem findings are vague, making it difficult to distinguish between child homicide and “Sudden Infant Death Syndrome (SIDS).” Levene and Bacon (2004), for example, have argued that up to 10 % of SIDS cases are undetected homicides in reality. Not just neonaticide, or infanticide, the cause of death of a substantial proportion of child homicides related to child abuse are often unidentified (Herman-Giddens et al., 1999; Jenny & Isaac, 2006). Therefore, it becomes difficult to charge these cases and even more difficult to prove the guilt, and hence these are often not registered as homicide cases, or sometimes they are recorded with other offenses (Porter & Gavin, 2010). This is particularly problematic in South Korea, as perpetrators of intra-familial filicides are rarely convicted for or proved guilty of murder. In many countries such as the U.S. (Malmquist, 2013), Canada (Dawson, 2015), and the U.K. (Brookman & Nolan, 2006), the legal categories for deliberate action and inaction are murder and manslaughter, respectively. In South Korea, however, the sentences involving child death were relatively light before 2014, when “Article 17 of the Child Welfare Act” was established, as before the introduction of this Article, most cases were considered as involuntary manslaughter (Lee, 2014). Although after 2015 voluntary manslaughter became increasingly attached to cases involving extreme neglect (such as leaving a seven-month-old baby at home alone intentionally; Bahk, 2019), the sentencing disparities remain wide (Lee, 2014). In line with the above, as each country and its legal jurisdiction has a unique system of cultural, social, and legal background that comes into play when judging child homicide, only examining the “sentenced homicide” or “criminal homicide” cases would possibly distort the reality. Examining all incidents that involve child death would be ideal. However, unfortunately, we do not have a system that collects and reviews all incidents involving children’s death in South Korea. Instead, the present study sought to obtain the original case file of all incidents that were judged to be initially suspicious (unusual death) from the forensic autopsy archive of the National Forensic Service (NFS). NFS is the institute that handles all the medico-legal autopsies in South Korea, and thus all the initially suspicious cases in South Korea are referred to this institute. It has a rich source of data, such as autopsy reports, reports from initial investigations, police reports, hospital reports, and interviews with family members, witnesses, perpetrators of the incidents, and so on. Therefore, utilizing this archive provides an opportunity to use the most comprehensive database in South Korea. To reclassify all incidents, we do not define each case by the legal definition of the criminal offense, which is more “perpetratorfocused” (Scott, 2018) and has cultural variability, but establish our own standard that is somewhat broader and more “childfocused,” based on extensive review or early studies of child homicide, child abuse, filicide, neonaticide, infanticide, etc. Our definition of child homicide is the death of any child under 18 that has died from another person’s deliberate action or inaction. To be more inclusive, we included not only incidents that are definitely homicide (category “Yes”) by clear evidence and documentation, but also cases involving suspicious circumstances (“Yes probably,” “Unknown but suspicious”). 1.2. Typologies of child homicide “Child-homicide” per se has not been researched in detail, with most studies focusing only on a part of the phenomenon, such as neonaticide—killing of a child in the first 24 h after birth (Bortoli, Coles, & Dolan, 2013; Vellut, Cook, & Tursz, 2012), maternal filicide (McKee & Egan, 2013), or death caused by physical abuse (Pierce et al., 2017), even though systematically examining diversity could contribute to broadening our understanding of this complex and intricate phenomenon. Several studies have, however, suggested typologies. For example, Lawrence (2004) derived six sub-categories of child homicide by reviewing previous research: neonaticide; fatal child abuse; “battered baby” or non-accidental injury; Family dispute and murdersuicide; psychiatric illness of offender; fatal sexual assault; and fatal teen assault. More recently, to reflect significant advances in the field Biron and Reynald (2016) revised Lawrence’s typology and recreated it to 8 categories: neonaticide; fatal child abuse; fatal neglect; domestic homicide; peer homicide; intimate partner homicide; acquaintance homicide; and stranger homicide: the first four essentially familial and the last four non-familial. Sidebotham et al. (2011, 2016) not only proposed an eight-fold typology but also tested the validity of this classification by analyzing the most comprehensive case series of fatal child maltreatment in England, Serious Case Reviews (SCR) over a 4-year period. The eight-fold typology is as follows: (1) Extra-familial child homicide (victim killed by someone other than a parent or parent figure, overly violent, some intention to kill accompanied with no attempt to conceal it); (2) Overt filicide (victim killed by parent or parent figure, overtly violent some intention to kill accompanied with no attempt to conceal it); (3) Severe, persistent child cruelty (killed by parents, especially involving step, adoptive, foster, and live-in partner of a biological parent perpetrating severe physical assault or neglect with evidence of previous physical abuse or neglect); (4) Covert filicide (killed by parent or parent figure, less overtly violent, with attempt to conceal the intention); (5) Extreme neglect (killed as a result of deliberate, persistent, or extreme deprivation); (6) Extra familial fatal assault (killed by someone other than parent or parent figure, with no clear intention); (7) Fatal physical abuse (killed while severe physical abuse is perpetrated but with no intention to kill); and (8) Maltreatment-related deaths (maltreatment related but not directly the cause of death). However, all these classifications were derived using a qualitative approach, such as by reviewing cases or previous literature and 2

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rarely using a quantitative approach, although Roach and Bryant (2015) tried a quantitative approach, conducting cluster analysis on over 1000 child homicides provided by the UK Homicide Index, to explore homogeneity among the cases using variables such as the age of the child victim, the circumstances of the killing, the ethnicity and age of the suspect(s), and the victim‐suspect relationship. They derived four distinct sub-groups. Their study is especially valuable in that it was a statistical attempt that little published research has ever tried. However, as the study solely relied on quantitative data and measures, the granular details about the nature and context of such crimes, which can be obtained from qualitative data such as narratives from investigator reports and documentary evidence such as suicide notes, may have been excluded. Furthermore, even though the UK Homicide Index, the national registries they used, is a rich source of data, many covert homicides, especially of children age under 1, can easily be hidden or might not have been included, and as we discussed earlier, it would not reflect a “complete picture” of the child homicide phenomenon. The abovementioned research, however, provides a useful frame that deepens our understanding of the multifaceted nature of child homicide. In Asia, research was relatively silent on this topic, and we are aware of no previous work conducted in South Korea. Since the typologies derived in previous literature are empirically based, South Korean typologies could be different in some aspects, with some characteristics of death. For example, some of the characteristics of child homicide are found to be universal such as the fact that children under the age of one, form the group with the highest victimization rate (Brookman & Nolan, 2006; Hwa et al., 2015; Paulozzi & Sells, 2002; Resnick, 1970). However, some aspects of child homicide are heavily influenced by cultural and social differences such as the influence of gun-ownership rate on the perpetrator’s pattern of attack (Liem & Reichelmann, 2014; Miller, Azrael, Hepburn, Hemenway, & Lippmann, 2006). Studies conducted in Asia, such as in Taiwan, China, and Japan, have demonstrated that firearms are rarely the cause of death as gun ownership is very low in these countries due to strict gun legislation; instead, the use of brute force was the more dominant cause for death (Hwa et al., 2015; Yasumi & Kageyama, 2009). In contrast, in the U.S. it has been reported that many adolescence deaths are caused by firearms (Hohl et al., 2017). Similarly, the typologies and related factors can change according to the culture of a place, and thus, there is a need to examine whether the typologies of child homicide in South Korea are different from those in other countries. We could obtain unprocessed original case files, which not only included basic descriptive and demographic information on the case, such as victims’ and perpetrators’ age and gender or location of crime, but also free text narratives of the case, such as reports of interviews with the perpetrator, which allows one to identify some key aspect of the crime and leads to a deeper understanding of motive for killing, presence of abuse, financial circumstance, and so on. Thus, a qualitative approach, such as an in-depth review of each case, can be adopted to delineate child homicide. However, in the present study, we chose to perform cluster analysis. Cluster analysis is a person-oriented examination that identifies or finds homogeneous groups with similar traits. As a data-driven approach, cluster analysis is suitable for confirming the multifaceted, heterogeneous nature of child-homicide. It does not require prior assumptions either and serves well as an exploratory tool. Cluster analysis is also useful to this situation where there is no previous research and hence a prediction is not available. Using verbal data of case records in statistical analysis can be challenging in many respects, and this might have been the reason why many previous studies that reviewed original case files might inevitably have adopted the qualitative approach and been descriptive. Thus, we established our novel analytic strategy that combined both qualitative and quantitative approaches (Fig. 1). First, we try to construct a wealth of information that reflects various aspects of child homicide phenomenon. Multiple variables would be extracted from qualitative analysis of reviewing all case files and this will yield the a dataset has “mixed” type of variables, mostly comprising “categorical” variables but also including several numerical (i.e., age of victims) or binomial (I.e., biological gender of victims and perpetrators) variables (Table 1). This holds especially true with many other data obtained in this field. In this case, the problem comes with clustering, because most of the clustering algorithms assume that the data used comprise either numerical or categorical variables (Akay & Yüksel, 2018). To solve this problem, we adopted Gower distance- designed for the treatment of mixed data, as a proximity index in clustering analysis (Gower, 1971). Since a cluster analysis has not been applied with a mixed-type dataset in the research on child homicide, this would be one of the novel points of the current study. Taken together, the study sought to the discern multifaceted nature of child-homicide in South Korea by adopting a more integrative approach by extracting variables reflecting various aspects of child homicide using a qualitative approach and identifying homogeneity among the child homicide cases using a novel statistical method based on a quantitative approach. 2. Method A retrospective study was carried out at the Forensic Medicine department of the NFS, South Korea. We reviewed all 341 records of children (aged 18 and under) brought to this institute for medico-legal autopsy from January 1, 2016, to December 31, 2016. In 2016, there were 2500 deaths of children aged 0–18, and as there are no official statistics of unusual deaths by age range, we cannot determine the exact number of all of the deaths judged to be un-usual deaths in children. However, in reality, most unusual deaths of

Fig. 1. Analytic strategies utilized in the current study. 3

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Table 1 Variables and definitions of the cluster analysis and the descriptions of the categories. Variable / definition

categories of coding

Nature and context of crime, abuse 1. Contribution of perpetrator’s actions to child death (contribution) : Participation in the perpetration of killing a child through action (beatings, a shaking injury, or suffocation,) or inaction (not providing necessary medical treatment, leaving a newborn unattended, or not providing necessary supervision for children) that is done knowingly 2. Cognition of murder : Aware that one’s action (beating, a shaking injury, or suffocation) or inaction (not providing necessary medical treatment, leaving a newborn unattended, or not providing necessary supervision for children) can cause death of the child 3. Abuse : If the children had experienced any type of abuse while living, not counting the killing incident Child abuse (experienced abuse of the child) 4. Physical abuse 5. Emotional abuse 6. Abandon 7. Neglect (except medical neglect) 8. Medical neglect 9. Neglect affected by alcohol 10. Negligence 11. Classification of covert homicide : Fatalities, using “less violent” means, or in which the cause of death is not immediately apparent. Death due to exposure, asphyxiation, drowning, strangulation, or poisoning, where there is some indication that there was some intent to kill (distinct from accidental deaths from these causes). Also included deaths following concealment of pregnancy, where there was any suspicion of the mother having killed the child.

(1) Yes (2) Yes Probably (3) Unknown Suspicious (4) Unknown Unlikely (5) No (6) Unknown (see Table 2 for the operational definitions)

(1) Yes (2) Yes Probably (3) Unknown Suspicious (4) Unknown Unlikely (5) No (6) Unknown (see Table 2 for the operational definitions)

(1) Yes (2) Yes Probably (3) Unknown Suspicious (4) Unknown Unlikely (5) No (6) Inconclusive (see Table 2 for the operational definitions) All (1) Yes (2) Yes Probably (3) Unknown Suspicious (4) Unknown Unlikely (5) No (6) Inconclusive (see Table 2 for the operational definitions)

(1) Neonaticide: homicide within the first 24 hours of life) (2) Infanticide: killing of a child below one year of age) (3) Covert filicide: killing an older child using “less violent” means, or in which the cause of death is not immediately apparent)

In the case of neonaticide 12. Mode of neonaticide 13. Reaction to pregnancy 14. Unwanted baby

(1) Passive: death due to medical, nutritional, physical, and emotional neglect (2) Active: deliberate killing (1) Lack of prenatal care (2) Denial of pregnancy (3) Unknown (1) Wanted (2) Unwanted (3) Unknown (1) Previously inflicted abuse present (2) Sudden Infant Death Syndrome (SIDS) (3) Unknown (1) Biological mother (2) Biological father (3) Stepmother (4) Stepfather (5) Adopted father (6) Cohabiting unrelated adult (Biological mother’s boyfriend, father’s girlfriend) (7) Both parental figures (8) Sibling (9) Relative (10) Acquaintance (11) Teacher at educational institution where child is attending (12) Stranger (13) Unknown (1) YES (2) No or Unknown (1) YES (2) No or Unknown (1) YES (2) No or Unknown (1) multiple (2) weapon (3) battering (4) push (5) drowning (6) fire (7) poisoning (8) fall (9) neonate fall (10) asphyxia (11) ligature strangulation (12) other (13) Unknown (1) Trauma (2) Drowning (3) Asphyxia (4) Thermal Injury (5) Starvation/ neglect (6) SUDI (7) Poisoning (8) Natural (9) Decomposed (10) Combined (11) Unknown

15. Death not caused directly by child abuse 16. The relationship of the main accused with the victim

17. 18. 19. 20.

Suicide attempted Suicide success Concealed child’s death Mean of murder

21. Cause of death – autopsy report

Child-related variables Child demographics 22. Sex 23. Age 24. Education

(1) Male (2) Female Continuous variable (1) None (2) Daycare (3) Kindergarten (4) Elementary (5) Middle school (6) High school (7) Unknown

Child risk factors 25. Physical: Physically disturbed (1) Encephalopathy (2) Premature_baby (3) Surgery_experience (4) Unknown 26. Develop: Developmental problem (1) Yes (2) No or Unknown 27. Mental: Mentally disturbed (1) Yes (2) No or Unknown 28. Suicide risk: If any of the following (1) Parental separation (2) (1) Yes (2) No Experienced Bullying (3) Truancy (4) Suicide ideation or previous attempt is relevant to the child Perpetrator(s)-related variable (maximum 2 perpetrators coded per each case; p1= perpetrator 1, p2 = perpetrator 2)

(continued on next page) 4

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Table 1 (continued) Variable / definition

categories of coding

Perpetrator(s)’ crime-related information. 29 (p1). 30 (p2). Homicide: If the person is involved in the killing 31 (p1). 32 (p2). Abuser: If the person is involved in abusing the victim

All (1) Yes (2) Yes Probably (3) Unknown Suspicious (4) Unknown Unlikely (5) No (6) Inconclusive (see Table 2 for the operational definitions)

Perpetrator(s) demographic 33. Age (p1) 34. Age (p2) 35 (p1). 36 (p2). Sex 37 (p1). 38 (p2). Relationship to victim 39. Education (p1) 40 (p1). 41 (p2). Job 42 (p1). 43 (p2). Job risk

(1) 7–19 (2) 20–26 (3) 27–33 (4) 34–40 (5) 41–47 (6) 48–54 (1) 5–19 (2) 20–26 (3) 27–33 (4) 34–40 (5) 41–47 (6) 48–54 (7) above 55 (1) Male (2) Female (1) Biological mother (2) Biological father (3) Step, adopted, cohabiting adult who is the intimate partner of one of the child’s parents (4) Relative (5) Acquaintance (6) Stranger (1) Middle school (2) High school dropout (3) High school completed (4) Undergraduate attending or drop out (5) Undergraduate completed (6) Graduation completed (1) None (2) Unskilled (3) Semi-skilled (4) Skilled (5) Professional (6) Unknown If the perpetrator is unemployed or has not enough ability to get a proper job All (1) Yes (2) No or Unknown

Perpetrator 1′s mental health 44. Depression 45. Suicidal ideation 46. Suicide attempt 47. Psychotic symptoms 48. Murder ideation 49. Personality disorder 50. Hostility Abuse perpetrated by each perpetrator 51. 52. Physical abuse 53. 54. Emotional abuse 55. 56. Abandon 57. 58. Neglect (except medical neglect) 59. 60. Medical neglect 61. 62. Negligence

All (1) Yes (2) Yes Probably (3) Unknown Suspicious (4) Unknown Unlikely (5) No (6) Inconclusive (see Table 2 for the operational definitions)

Household risk factors (Known Problems and risk factors in family and stability of care) All (1) Yes (2) No or Unknown 63. Mental health problems Any member of household identified as having an MHP such as those listed in 64. DV the Diagnostic and Statistical Manual of Mental Disorders [4th ed.; DSM-IV; 65. IPPS (intimate partner problem) American Psychiatric Association, 1994] 66. Financial Domestic violence in the family, history of domestic violence, partner 67. Caregiver violence in the family 68. Step The caregiver in the household experiencing problems with a current or 69. Young former intimate partner, such as a divorce, break-up, argument, jealousy, 70. Skill conflict, or other discord at the time of the incident Economic difficulty, unemployment, financial stress Caregiver characteristics, the non-biological adult is the major caretaker or biological parents but are unable to give proper care One or both parents are not biological parents (step, adopted, partner) Biological mother’s age under 27 Parental incompetence, noticeable lack of motivation and parenting skill

children are subjected to an autopsy in Korea, the 341 cases of autopsy in NFS (which is 14 % of all deaths) can be viewed as the proxy number of all unusual deaths. Data collected from forensic autopsy records include victim identity, sex, age, place of the event, the relationship between the victim and the offender(s), sex of the offender(s), age of offender(s) the anatomical region(s) injured, the cause of death. Several documents were also analyzed, such as transcripts of interviews by police and interrogation by the investigating judge of the offender (s) and witnesses (offender(s)’ companion or husband, family members, friends, work colleagues, neighbors, first responders at the scene of the child’s death). 2.1. Definition of child homicide in our study Child death can occur not only by active assault but also by passive inaction, especially as newborns or infants lack the ability to care for or defend themselves. We define child homicide as follows in the current study: Cases are regarded as child homicide if (a) perpetrator(s) knowingly committed 1. an action that contributed to death of a child (children), such as through beatings, a shaking injury, or suffocation, or 2. an inaction that contributed to the death of a child (children) by not providing necessary medical treatment, leaving a newborn unattended, or not supervising the child (children). 5

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Table 2 Operational Definitions of maltreatment related variables (numbered 1–10, 29–32, and 51–62). Category

Definition

(1) Yes:

Clear evidence and documentation through medical, child protection, law enforcement, or medical examiner records that indicate murder was committed/ abuse occurred/ abuse caused, and contributed to the homicide incident Not enough evidence to make a definitive assessment with potentially conflicting information. Clear demonstration of unusual, questionable, and/or suspicious factors present that strongly suggest the murder was committed/ abuse occurred/ abuse caused, contributed to the homicide indecent. No documentation, lack of information from sources indicating murder was committed/ abuse occurred/ abuse caused, contributed to the homicide indecent, but multiple known risk factors or other suspicious evidence is deduced from the records leading to suspicion. No documentation, lack of information from sources indicating murder was committed/ abuse occurred/ abuse caused, contributed to the homicide indecent, and no known risk factors or other suspicious evidence is deduced from the records. Clear evidence and documentation through medical, child protection, law enforcement, or medical examiner records that murder was not committed/ abuse had not occurred/ abuse had not caused, contributed to the homicide indecent. No suspicious or known risk factors present or clearly explained how they are not associated with the death Inconclusive due to lack of documentation or information from sources

(2) Probably Yes: (3) Unknown but suspicious: (4) Unknown but unlikely: (5) No: (6) Inconclusive:

Based on the above definition, two coders, who had completed a master’s degree on clinical psychology and social psychology respectively, judged each case and categorized them into six types: “Yes” “Probably Yes,” “Unknown but suspicious,” “Unknown but Unlikely,” “No,” and “Inconclusive” (see Table 2). These or other similar categories are widely used in fatal and nonfatal child maltreatment surveillance and research (Parrish et al., 2017; Schnitzer, Slusher, Kruse, & Tarleton, 2011). The cases included for analysis were those under the categories “Yes,” “Probably Yes,” and “Unknown but suspicious.” Later, all of the cases included as child homicide were checked again and screened by two medical examiners to determine whether these cases are at least suspicious from the forensic examiner’s perspective, and all were confirmed to be at least suspicious child homicide cases. 2.2. Measures To extract relevant factors and use them for statistical analysis, we developed a coding scheme of variables in the following manner: first, we selected various key variables based on an extensive review of previous literature on child abuse, fatal maltreatment, neonaticide, infanticide, filicide, homicide, familicide, and homicide-suicide, to understand the multifaceted nature of child homicide. Next, we defined each variable and the categories under which they were classified. All the variables derived and used are listed in Table 1 and divided into four main domains: (a) Nature and context of crime, abuse (b) Victim demographic / risk factors (c) Perpetrator(s) demographic/ risk factors/ act of their abuse on child (d) Known problems in family and stability of care. Except for a few variables (i.e., victim’s age), the rest are categorical variables (see Table 1). Each case was reviewed independently by two researchers (a clinical psychologist and a social psychologist) using the classification system. Where there was a discrepancy between the two coders, they discussed the case together and assigned again. 2.3. Interrater reliability Among the 341 children who were subjected to an autopsy, 95 (28 %) were found to be murdered, according to our definition (Intra-class correlation: ICC = .90 between two coders). 2.4. Clustering strategy Our study aimed to resolve the heterogeneity data question and derive meaningful subgroups in the South Korean child homicide data. As the dataset is mixed and contains not only continuous variables but also binary, ordinal, and categorical variables, Euclidian distance, which deals only with the numerical type of variable, was not suitable; therefore, the Gower distance (Gower, 1971)—designed for treatment of mixed data—was calculated to measure the dissimilarity. A low value indicates that the two variables are similar, and a high value indicates that the two are completely different. As the clustering method, we chose PAM (partitioning around medoids; Kaufman & Rousseeuw, 2005). With PAM, we could perform clustering using the Gower distance metric, which is not possible with other algorithms, for example, KMEANS, which allows only Euclidean and Manhattan Distance. Moreover, PAM has the ability to eliminate the influence of outliers and noises, as it uses data points to be medoids as the cluster center, rather than the mean value of clusters, which makes it sensitive to outliers. In each cluster, the data point that is the medoid is at a minimal distance from all other data points within the cluster. This robustness is particularly important when many elements do not belong completely to any cluster because of the complexity of the phenomenon, such as child homicide in this study. Because of the high dimensionality of our dataset, it was considered suitable to adopt PAM. Furthermore, PAM is known to be effective in dealing with a relatively small dataset such as ours. 6

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3. Results 3.1. Basic demographics of victim, perpetrator During the one-year period from January 1, 2016, to December 31, 2016, 341 autopsies of children aged 0–18 were conducted at the institute. In total, 95 child victim cases were judged as homicide cases based on our definition and criteria, which accounted for 27.9 % of all cases we reviewed. The ages of the victims were not normally distributed; the median age was 0 years (IQR = 5.5, range 0–18), and 50 were boys (median age = 1.5, IQR = 5, range = 0–18) and 45 were girls (median age = 0, IQR = 6, range = 0–18). All of the perpetrators (141) were adults. The mean age of the perpetrators was 32.11 (8.59); and 85 were female, 54 were male, and three were unknown. 3.2. Cluster analysis Five outlier cases were excluded to improve clustering accuracy measured by the silhouette index (Liu, Li, Wu, & Fu, 2018). Because of the complexity of the child homicide phenomenon and the resulting complexity of our data, the average silhouette width was low, but it was within the acceptable range, which is 0.21 and 0.20 for two and eight clusters, respectively. When examining the contents of each cluster, the 8-cluster solution seemed more suitable for exploring the diversity of the child homicide phenomenon and for providing a detailed description. Thus, we chose the 8-cluster solution. 3.2.1. Cluster 1 torture: torturous filicide resulting from prolonged and severe child abuse Children in this cluster were killed as a result of extreme, severe abuse for an extended period, and 12 deaths (13.3 %) were assigned to this category. They experienced the most abuse compared with those of other clusters (Table 3). For example, all 12 children experienced severe pain and suffering due to the prolonged and repeated physical abuse, which were intentionally inflicted and followed by medical neglect; six children were deprived of food and water, and all children were neglected physically with no proper clothing and inappropriate hygiene. However, these characteristics observed in Torture are surprisingly similar to the “Child torture” abuse defined by Knox et al. (2014). Child torture is a type of abuse that dehumanizes and denigrates children and involves a long period of physical and psychological abuse, including the deprivation of essential needs to obtain submission and control. Therefore, cluster 1 in the current study is described as “Torturous filicide resulting from prolonged and severe child abuse” and is named Torture. The probability of risk factors was maximum in this cluster (Table 3). For example, this is the largest cluster in which the child’s parental figure is not biologically related to the child (i.e., adoptive parents, step-parents, partner of a parent who is not the biological parent of the child, Table 3: Step). Moreover, in 11 out of the 12 children’s households, the parental figures lived together but were unmarried or were live-in partners of the biological mother/father after divorce (Table 3: IPPs). This characteristic also matches the results of the study on child torture by Knox et al. (2014) that demonstrated that most of the perpetrators (79 %) were not a firstdegree relative but were, for example, stepparents, live-in partners, or relatives. Regarding the crime-relevant aspect, this cluster is the second largest one that attempted to conceal the child’s death (5 cases, 41.7 %) or did not take immediate emergency measures, following cluster 3 Neonaticide (Table 3). Suicidal tendency is low in this cluster (Fig. 5). Only one couple tried to commit suicide, and the motivation was the fear of being discovered that they lied about their child being missing when the media and police started to notice when, in fact, they had abused the child and buried the body on a mountain. Since they failed in their attempt to commit suicide, no perpetrator in this cluster is dead due to the incident. The mean age of the perpetrator was 30.5 years (Fig. 3 Left). 3.2.2. Cluster 2 – maternal filicide This is the smallest cluster and has seven children in it. All the perpetrators are the “biological mother,” and they were found to have depression and mood disorders (two with depression; two, postpartum depression; one, psychotic symptoms) or alcohol problems with marital conflict (two with husbands having affairs) (Table 3). Except one, all perpetrators had suicidal ideation, and four had tried to commit suicide after the child’s death, and two had succeeded (Fig. 5). One of the perpetrators killed two of her children one of them was infant the other’s age was three years old. Severe marital conflict and mental health issues of the mother led to not only physical neglect, such as not providing necessities of life such as food, shelter, warmth, supervision, but also lack of emotional support and nurturing (emotional neglect) (Table 3). However, no obvious physical injuries or traces of physical abuse were observed. The cause of death was less violent than that of Torture (two drowning, two asphyxia, one falling, one from carbon monoxide poisoning, and one house fire with evidence of arson (Fig. 4). All reported to the police or hospital right after the incident, and no perpetrator tried to conceal the crime. The mean age of the perpetrator is 36 years, which is the second-highest among the clusters (Fig. 3). 3.2.3. Cluster 3 neonaticide: by biological mother Similar to Maternal filicide, all perpetrators are the “biological mother.” It is the biggest cluster in which 18 children (20 %) are included, and all perpetrators were the biological mother. Perpetrators in this cluster are the youngest, with mean age 22, and among 12 whose ages were known seven were under 18, which is in line with previous research that neonaticidal women are typically young and often unmarried (Fig. 3). Previous research has also consistently demonstrated that women who commit neonaticide evidence less depression, psychotic illness, or suicidal attempts than do mothers who have killed an older child (Beyer, Mack, & Shelton, 2008; Bourget & Labelle, 1992; Cheung, 1986; D’Orbán, 1979; Haapasalo & Petäjä, 1999; Resnick, 1970; Spinelli, 2001). The current study 7

Maternal Filicide (n = 7)

Neonaticide (n = 18)

8

Not Abused

Not Abused

Inconclusive

3 (25/3.3 %) 9 (75/10 %) 0

0

Inconclusive

Abused

12 (100/13.3 %) 0

Abused

7 (100/7.8 %) 0

3 (42.9/3.3 %) 3 (42.9/3.3 %) 1 (14.3/1.1 %) 0 18 (100/20 %) 0

0

17 (94.4/18.9 %) 1 (5.6/1.1 %) 0

Child Risk Factors: Known child-related risk factors, frequencies per each cluster (percentage within 25. Physical handicap 0 0 3 (16.7/3.3 %) 26. Developmental problems 0 0 0

10. Negligence

8. Medical Neglect

Child Abuse: Known frequencies per each cluster (percentage within the cluster/ percentage of total Abuse type Judgment 4. Physical Abused 12 2 1 (100/ 13.3 (28.6/2.2 %) (5.6/1.1 %) %) Inconclusive 0 3 17 (42.9/3.3 %) (94.4/18.9 %) Not Abused 0 2 0 (28.6/2.2 %) 5. Mental Abused 11 5 0 (91.7/12.2 (71.4/5.6 %) %) Inconclusive 1 1 18 (8.3/1.1 %) (14.3/1.1 %) (100/20 %) Not Abused 0 1 0 (14.3/1.1 %) 7. Neglect Abused 12 7 3 (100/13.3 %) (100/7.8 %) (16.7/3.3 %) Inconclusive 0 0 15 (83.3/16.7 %) Not Abused 0 0 0

Torture (n = 12)

Table 3 Profiles of child homicide cases across the eight cluster solutions.

9 (100/10 %) 0

%)

%)

%)

%)

%)

%)

8 (80.0/8.9 %) 2 (20.0/2.2 %) 0

8 (80.0/8.9 %) 2 (20.0/2.2 %) 0

8 (80.0/8.9 %) 2 (20.0/2.2 %) 0

8 (80.0/8.9 %) 0

2 (20.0/2.2 %)

2 (20.0/2.2 %) 0

8 (80.0/8.9 %)

Paternal Infanticide (n = 10)

the cluster/ percentage of total 90 children) 3 1 2 (17.6/3.3 %) (11.1/1.1 %) (20.0/2.2 %) 1 1 2 (5.9/1.1 %) (11.1/1.1 %) (20.0/2.2 %)

5 (29.4/5.6 %) 12 (70.6/13.3 %) 0

2 (11.8/2.2 %) 15 (88.2/16.7 %) 0

2 (11.8/2.2 %) 15 (88.2/16.7 %) 0

%)

0

15 (88.2/16.7 %) 0 3 (33.3/3.3 7 (77.8/7.8 1 (11.1/1.1 1 (11.1/1.1 2 (22.2/2.2 1 (11.1/1.1 6 (66.7/6.7 0

2 (22.2/2.2 %) 3 (33.3/3.3 %) 6 (66.7/6.7 %)

15 (88.2/16.7 %) 0 2 (11.8/2.2 %)

4 (44.4/4.4 %)

Paternal Filicide (n = 9)

2 (11.8/2.2 %)

90 children)

No previous abuse (n = 17)

%)

%)

%)

%)

%)

2 (22.2/2.2 %) 1 (11.1/1.1 %)

5 (55.6/5.6 1 (11.1/1.1 3 (33.3/3.3 8 (88.9/8.9 1 (11.1/1.1 0

0

7 (77.8/7.8 %) 1 (11.1/1.1 %) 9 (100/10 %) 0

4 (44.4/4.4 %) 1 (11.1/1.1 %)

0

5 (55.6/5.6 %)

Maternal Infanticide (n = 9)

7 (7.8 %)

2 (25.0/2.2 %)

(continued on next page)

11 (12.2 %)

0

66 (73.3 %)

24 (26.7 %)

10 (11.1 %)

31 (34.4 %)

49 (54.4 %)

1 (1.1 %)

40 (44.4 %)

49 (54.4 %)

5 (5.6 %)

58 (64.4 %)

27 (30 %)

9 (10 %)

47 (52.2 %)

34 (37.8 %)

All (n = 90)

0

8 (100/8.9 %) 0

0

8 (100/8.9 %) 0

0

1 (12.5/1.1 %) 7 (87.5/7.8 %) 0

8 (100/8.9 %) 0

0

8 (100/8.9 %) 0

0

Psychotic (n = 8)

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2 (16.7/2.2 %) 7 (58.3/7.8 %)

Torture (n = 12)

0

0

Maternal Filicide (n = 7)

1 (5.6/1.1 %)

0

Neonaticide (n = 18)

9

Number of cases (proportion within/ total 90 cases).

Household Risk Factors: Known problems of the household where the child belongs, frequencies per 63. Mental health problems 5 6 2 (41.7/5.6 %) (85.7/6.7 %) (11.1/2.2 %) 0 2 64. DV 4 (33.3/4.4 %) (11.1/2.2 %) 65. IPPs 11 6 15 (91.7/12.2 (85.7/6.7 %) (83.3/16.7 %) %) 66. Financial hardship 8 2 9 (66.7/8.9 %) (28.6/2.2 %) (50.0/10 %) 67. Caregiver 11 6 15 (91.7/12.2 (85.7/6.67) (83.3/16.7 %) %) 68. Step (step, adoptive, foster, live-in boy/ 8 0 0 girlfriend) (66.7/8.9 %) 2 10 69. Young (under 27) 9 (75.0/10 %) (28.6/2.2 %) (55.6/11.1 %) 70. Skill (lack of parenting skill) 11 3 4 (91.7/12.2 (42.9/3.3 %) (22.2/4.4 %) %)

28. Suicide risk index

27. Mental health problems

Table 3 (continued)

1 (11.1/1.1 %) 1 (11.1/1.1 %) 2 (22.2/2.2 %)

1 (5.9/1.1 %) 8 (47.1//8.9 %) 2 (11.8/2.2 %)

2 (20.0/2.2 %) 8 (80.0/8.9 %) 4 (40.0/4.4 %)

0 1 (12.5/1.1 %) 2 (25/2.2 %)

0 5 (55.6/5.6 %) 9 (100/10 %)

6 (66.7/6.7 %) 6 (66.7/6.7 %)

4 (50.0/4.4 %) 7 (87.5/7.8 %)

3 (30.0/3.3 %) 5 (50/5.6 %)

7 (87.5/7.8 %) 0

1 (12.5/1.1 %) 1 (12.5/1.1 %)

Psychotic (n = 8)

7 (77.8/7.8 %) 3 (33.3/3.3 %)

0

0

Maternal Infanticide (n = 9)

6 (35.3/6.7 %) 2 (11.8/2.2 %)

2 (20.0/2.2 %) 2 (20.0/2.2 %)

Paternal Infanticide (n = 10)

7 (87.5/7.8 %)

1 (11.1/1.1 %) 3 (33.3/3.3 %)

Paternal Filicide (n = 9)

each cluster (percentage within the cluster/ percentage of total 90 children) 0 8 0 4 (88.9/8.9 %) (44.4/4.4 %) 0 0 0 2 (22.2/2.2 %) 5 4 5 7 (29.4/5.6 %) (44.5/4.4 %) (50/5.6 %) (77.8/7.8 %)

0

0

No previous abuse (n = 17)

37 (41.1 %)

44 (48.9 %)

12 (13.3 %)

55 (61.1 %)

45 (50 %)

60 (66.7 %)

8 (8.9 %)

32 (35.6 %)

14 (15.6 %)

6 (6.7 %)

All (n = 90)

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also supported the results that the most common motive for filicide was to get rid of an unwanted child, and there were no cases of perpetrators with suicide motivation (Fig. 5). All perpetrators who were adults were unemployed, lived in poverty; they did not have a home and stayed at an accommodation. Most children died of suffocation or abandonment (Fig. 4). Head trauma was also identified as one of the methods used. This cluster has the highest proportion of perpetrators trying to conceal their crime (12 out of 18, 66.7 %, Fig. 5). In sum, it is a relatively well-defined cluster identified as one of the subtypes of child homicide in other countries as well as in South Korea (Putkonen et al., 2016). 3.2.4. Cluster 4 no abuse: death not related to previous child abuse (negligence, homicide-suicide) This cluster is the second largest one following Neonaticide (17 children, 18.9 %). The “deaths were not related directly to previous child abuse perpetrated by the perpetrator” other than this incident. It is the only cluster in which a non-family member (i.e., teacher, acquaintance) is included as the perpetrator. Regardless of the pattern of incident in this cluster, case in this cluster had lack of information from the relevant report thereby, evidence of familial problems or previous child abuse history could not be identified, and thus, in comparison with other clusters, the proportion of risk factors and history of child abuse (Table 3) is least observed. In two incidents in this cluster, multiple children were killed at the same time. In one incident, as parents killed two of their children and committed suicide due to the economic hardship, the whole family died. In another incident, the mother killed two of her children and committed suicide by driving car into the sea where three of them were riding. The major cause of death is less violent, such as asphyxiation, suffocation, suspicious sudden infant death syndrome (SIDS), and smoke inhalation (Fig. 4). 3.2.5. Cluster 5 paternal filicide: overt filicide by paternal figure (-suicide) Nine children are included in this “filicide by paternal figure cluster.” Both perpetrators (mean age: 45) and victims (median age: 10) are the oldest among all the clusters (Fig. 3). Further, risk factors such as marital, financial, and employment problem proportions are the highest in this cluster (Table 3). The mental state of the perpetrators could be attributed to socioeconomic difficulties. Except for one stepfather, all of the others had psychiatric illnesses (gambling addiction 1, alcohol addiction 1, depression 4, and schizophrenia 1). Six out of eight had tried to commit suicide and succeeded (Fig. 5). One of the two remaining did not commit suicide but suffered psychosis, and the other was a stepfather. In the case of the stepfather, he was found to be stressed by the child’s rare physical handicap and abused the child for a prolonged period. Among the victims, three children had a chronic physical, developmental, or mental illness, and their illness was the main cause of their father’s depression (Table 3). Four children died of head injuries caused by hitting with a blunt instrument, two died of asphyxia (one ligature strangulation, one suffocated with a plastic bag), one by carbon monoxide poisoning, one death by fire, and one by stabbing with a sharp object (Fig. 4). This cluster, in sum, used overtly violent means, did not attempt to conceal the homicide, and showed a clear intention to kill. The cluster also includes extended suicide (Fig. 5). 3.2.6. Cluster 6 paternal infanticide: Infanticide, battered baby, or non-accidental injury (mainly paternal figure) Ten infants (11.1 %) had been abused for an extended period by a main parental figure. All perpetrators claimed that the death was a “mistake” or “not intentional”; however, evidence of previous inflicted injuries (e.g., healing fractures), which include bruising, fractures, dislocations, and ruptures, or long-term neglect (e.g. lack of hygiene, low weight), reflected parental incompetence and past assaults. Most of the perpetrators were “male” (7 out of 10, 70 %), and in these cases fatal abuse occurred while paternal figure (biological father, stepfather, partner) was taking care of the infant instead of the mother figure, as they were unemployed (Fig. 2 and Table 3). This supports previous research claiming that fathers’ parenting stress is significantly associated with greater use of corporal punishment (Lee, Perron, Taylor, & Guterman, 2011). Physical abuse, neglect (physical, medical), and negligence combined and caused death (Table 3). Perpetrators’ mean age is 28, which is second youngest after the Neonaticide cluster (Fig. 3). Although the perpetrator in this cluster had unemployment problems, they did not show any obvious mental health issues like the parents in Paternal filicide cluster and tended to have a small proportion of identified risk factors in the household (Table 3).

Fig. 2. Gender proportions (frequencies) of perpetrators (left) and victim (right) in each cluster. 10

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Fig. 3. Boxplots of the Age distributions of Perpetrator (left) and victim (right) in each cluster (median age of each cluster above the plot).

Fig. 4. Mosaic plot of the proportions of the cause of death for each of eight clusters.

Fig. 5. Sankey diagram showing the relationship showing that each eight clusters, and whether they tried (or unknown) to conceal that they have killed the child (Conceal) and among them, how many of them attempted (or did not attempted) suicide, and among them how many of them succeeded (failed, or unknown) suicide. The width of the colored line shows the proportion of the cases. 11

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3.2.7. Cluster 7 maternal infanticide: Infanticide, negligence, and neglect (mainly biological mother) This cluster is similar to the Paternal infanticide cluster in that all nine (10 %) victims were infants; however, the majority of the perpetrators were the biological mothers (8, 88.9 %, one biological father), and while this type of abuse was more impulsive and active violence in Paternal infanticide, a more passive type of abuse such as neglect or negligence caused the death in this cluster (Table 3). For example, in one case, an unmarried, young single mother left a 2-month-old alone at home for several hours regularly to hang out with her friends. Lack of prenatal care was found in many cases. Incompetence in parenting skills is reflected in the unsafe and unhygienic home environments of the victims (Table 3). The most different aspect between Paternal infanticide and this cluster was the risk factor of “intimate partner problems” (IPPs, Table 3). IPPs were found more in these maternal filicides, such as the biological father and mother are not legally married and live separately, which is relatively rare in South Korean culture, where people believe in being legally married when a child is born (Ma, Andersson, & Neyer, 2014). Also, disputes or conflict with the partner were observed in 80 % of the cases. Moreover, unlike perpetrators in Paternal infanticide who did not have mental health issues, several perpetrators in Maternal infanticide were identified to have depression and anxiety problems (Table 3). 3.2.8. Cluster 8 psychotic killing: Acute psychotic killing accompanying suicide attempt Eight victims (8.9 %) were identified to be in this cluster. The proportion of females was relatively higher, as four were female and two were male (Fig. 2). All of them deliberately, overtly killed the children with clear intention to kill, in the obvious psychotic state they presented. Severe depressive, psychotic symptoms (distorted cognition due to depression and schizophrenia) were the most prominent contributor for five perpetrators, and the other two had strong stressors related to intimate partner problems (partners of both were involved in affairs), which contributed to the homicide in a burst of spousal revenge. Most of the victims were not identified as having been abused (Table 3), and the means of the murders were less violent. The major cause of death of the child in this cluster was asphyxiation (Fig. 4). All perpetrators tried to commit suicide, but only three succeeded (Fig. 5). In one incident in this cluster, a mother killed two of her children as she was suffering by this delusional thinking that somebody would kill her children unless she kills first. 4. Discussion The current study examined all the autopsy and police reports of 341 children on whom forensic autopsy was conducted in the year 2016. This is the most comprehensive quality data from South Korea. Based on the definition of the current research, 95 children were found to be victims of homicide. The estimated resident population of South Korea aged 0–18 years in 2016 was approximately 9,180,000 (Statistics Korea, 2017). Taking this as a baseline, the annual incidence of child homicide is 1.03 cases per 100,000 children (0–18 years). Since we did not review all the deaths of children, and as many cases are never discovered, some child homicides may not have been included in this study and hence may have been overlooked. However, it is meaningful that this is the first study that endeavors to examine the prevalence and the current state of child homicide in South Korea. The major perpetrator of child homicide in South Korea was a family member (biological parents, relatives, or cohabiting partners of parents) of the child. Among 95 cases, all except three children were killed within the family. This is in line with existing research conducted in other countries indicating that children are usually killed by a parent or a step-parent (Alder & Polk, 2001; Wilczynski, 1997). However, although children are normally killed by a family member, it is surprising how few (only four cases) children were killed by extra-familial members compared to Euro-American countries. Previous research has indicated that the proportion of familial homicide is generally larger in East-Asia and the Pacific than in Euro-American countries. A recent global systematic review describing the perpetrators of child homicide revealed that familial homicide in East-Asia and the Pacific was 61.6 % (parents 61.7 %, family no parents 5.9 %; Stöckl, Dekel, Morris-Gehring, Watts, & Abrahams, 2017). These ratios were 49.3 % (parents 27.6 %, family no parents 21.7 %) in the Americas and 16.7 % (parents 16.7 %, family no parents 0 %) in European countries. One factor that contributes is the Asian cultural background where family inter-dependence is high. For example in South Korea, children over 20 years of age normally live with their parents, and they are supported economically until they get married, and the normal age range of first marriage in South Korea is over 30; 33.2 and 30.4 years for males and females, respectively (Statistics Korea, 2017). Subsequently, parents take care of their children, and children rely on their parents, both emotionally and economically, into their thirties. This long-term, strong inter-relationship means that parents have high expectations of their children and play a large part in their lives. Thus, parents’ responsibility for their children and their belief that they are entitled to make decisions about their children’s lives, even when to end their life, might contribute to parental abuse and homicide. In addition to cultural factors, social factors such as restrictions on the ownership of firearms can decrease extra-familial child homicide. South Korea and Japan have the strongest firearm legislation in the world, and subsequently, not only with child homicide cases but also with all of the 341 autopsies in 2016, none involved firearms. The overall rate of homicides involving firearms in South Korea is only 0–0.1 %. In comparison, in the U.S., from 2010 to 2012, 86 % of all adolescent homicide involved firearms and 97.5 % of total adolescent homicide in the Philadelphia, U.S. (Hohl et al., 2017). Drug consumption in South Korea is so low that it is often called the “country free from the needle,” and this might also affect adolescent homicide (Kim et al., 2015) as drug misuse is strongly related to adolescent homicide (Hohl et al., 2017). Low rates of drug use and household firearm ownership are likely to be the contributing social factors that led to the numbers of extra-familial child homicide in the present study. In this respect, the various cultural and social factors that affect the patterns and prevalence of child homicide indicate that continuing the endeavor of comparing the trends in child homicide between different cultures can help to identify how specific factors affect the phenomenon. As this is the first study conducted in South Korea, we did not know a priori the natural groupings or subtypes and wanted to form 12

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a typology that represents different patterns in the data; thus, a cluster analysis was performed with 90 cases. The novelty of this study lies in its clustering of variables of a mixed dataset derived from both quantitative and qualitative approaches by extraction from autopsy reports and police investigations; therefore, eight clusters were identified. Cluster 1 Torture: Torturous filicide resulting from prolonged and severe child abuse Cluster 2 Maternal filicide Cluster 3 Neonaticide: by biological mother Cluster 4 No abuse: Death not related to previous child abuse (negligence, homicide-suicide) Cluster 5 Paternal filicide: Overt filicide by a paternal figure (-suicide) Cluster 6 Paternal infanticide: Infanticide, battered baby, or non-accidental injury (mainly paternal figure) Cluster 7 Maternal infanticide: Infanticide, negligence, and neglect (mainly biological mother) Cluster 8 Psychotic: Acute psychotic killing accompanying a suicide attempt Although we focused on the differences between the findings of the current study and those from previous studies conducted in different cultures, many similarities were observed with the descriptions of each of the eight clusters and the previous findings of similar sub-types of child homicide. However, the cluster corresponded with the description and definition of “child torture” by Knox et al. (2014), and an example of a detailed case report of child torture is as follows: A 6-year-old boy was found buried in a mountain and later found to have been repeatedly abused by his step-mother, and the biological father also participated regularly for over two years. For the three months before death, he was isolated in the cold bathroom without a heater and hot water, being naked, and the outside temperature during the period ranged from 4 °F to 14 °F. The reason they first locked him inside the bathroom was that he peed on himself. Whenever he tried to come out, they punched or beat him with sticks so that rib, clavicle, and head fractures occurred. No adequate hygiene, clothing, supervision, education, or medical care was provided. They poured a bottle of bleach constantly on the boy, which caused chemical burns on the skin. Death was caused by combined physical injuries such as abusive head trauma, malnutrition, scars and bruises all over the face and body, and hypothermia. Child torture research is still in its infancy and based on our research the characteristics and patterns are strikingly similar to those described by Knox et al. (2014) regardless of the cultural differences. More research is necessary for this specific type of abuse because this cluster has the cruelest and most malicious sentiment, and there is a possibility that this cruelty might be ubiquitous. On the other hand, regardless of meaningful differentiation between clusters that merged from our novel statistical approach, the eight sub-clusters are not entirely distinct from each other, but there is some overlapping of group characteristics. We shall discuss in the following paragraphs these similarities and differences across clusters: 1. Gender of the perpetrators (Mainly female in clusters Maternal filicide, Neonaticide, Maternal infanticide, Psychotic killing, mainly male in clusters Paternal filicide, Paternal infanticide), 2. Suicidal tendencies (clusters Maternal filicide, Paternal filicide, Psychotic killing), 3. Victim’s age under one and others (neonaticide and infanticide: clusters Neonaticide, Paternal infanticide, Maternal infanticide, and others) 1 Gender of the perpetrators (female dominant in Maternal filicide, Neonaticide, Maternal infanticide, Psychotic killing VS male dominant in Paternal filicide, Paternal filicide). In keeping with results in previous literature, females were more likely to be the main perpetrators of child homicide as an entity, which is a distinctive aspect of child homicide unlike other forms of homicide in which the victim is an adult (Mariano, Chan, & Myers, 2014; Putkonen et al., 2016). However, when observing the pattern of crime, males tended to be more violent and impulsive when killing their children, which is also in line with previous studies (Putkonen et al., 2011). In the current study, the proportion of deaths caused by more cruel and severe forms of abuse was higher in clusters Paternal filicide and Paternal infanticide in which the perpetrator’s gender was mainly male than in clusters Maternal filicide, Neonaticide, Maternal infanticide and Psychotic killing in which the main perpetrator is female. Instead, in clusters where the main gender of the perpetrator is female, the cause of death was mainly asphyxiation, drowning, or other unknown causes with no previously inflicted injuries. Especially in clusters Maternal filicide, Paternal filicide, Psychotic killing, which accompany suicide tendency, the proportion of previously inflicted physical abuse is higher, such as in cluster Paternal filicide, in which a male is the main perpetrator, as compared to clusters Maternal filicide and Psychotic killing in which a female is the main perpetrator (Fig. 3). In addition, although “infants” are the main victims in both clusters, Paternal infanticide and Maternal infanticide, the proportion of physical abuse was higher in Paternal infanticide in which the main gender was male (Table 3). In sum, child homicide is less likely to be perpetrated by males; however, if it is perpetrated, it tends to be more violent and cruel and is accompanied by physical abuse. Meanwhile, not only with the pattern of the crime but also the triggers and risk factors are different between the genders. In current study, marital discord and conflict with spouses are also more often frequent contributors that trigger child homicide in these female-dominant clusters (Table 3). 2 Suicidal tendencies (accompanied in the clusters Maternal filicide, Paternal filicide, and Psychotic killing) The clusters that showed a high rate of suicide attempts, involving many serious, and successful, life events are Maternal filicide, Paternal filicide, And Psychotic killing. Victims’ and perpetrators’ ages tend to be higher in these clusters than in others (Fig. 2), and the homicide intention is overt and obvious. One of the common characteristics in these clusters is that they do not necessarily involve previous child abuse (Table 3). Meanwhile, in line with the findings from the literature, psychopathology is one of the strongest predictors for suicide attempts; these three clusters show a high rate of identified mental illness problems (Beautrais, 2000). A high level of depression, postnatal depression, alcohol abuse, and schizophrenia is identified in over 80 % of cases in these clusters (Table 3). On the other hand, Paternal filicide has the highest rate of suicide attempts that have been successful (Fig. 5), and the predominant risk factor was financial problems and unemployment. Like other male-perpetrator dominant cluster, method used for killing was more violent with Paternal filicide and the main cause of death in a house fire and violent 13

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trauma. The main causes of death in Maternal filicide and Psychotic killing are asphyxiation, drowning, or unknown with no evidence of previous abuse (Table 3). Further, unlike Paternal filicide, where the main contributor is unemployment and economic hardship, the more pronounced factor for these clusters was intimate partner problems (IPPs; Table 3). Marital discord and conflicts are reported to be one of the main factors affecting those sub-types of homicide when the main perpetrator is female (Krischer, Stone, Sevecke and Steinmeyer, 2007). However, the influence of IPPs in the current study might also partly be affected by Asian culture, and the concept that “it is the mother’s responsibility” to take care of their children and the values associated with male dominance are still prevalent (Cooke & Kim, 2017; Takahashi & Berger, 1996). For example, a report demonstrated that Japanese mothers feel extreme emotional pain, such as shame and humiliation, when they have marital conflict (divorce or separation) because they think they have failed at fulfilling their moral duty of providing adequate, good care to their children (Iga, 1996; Takahashi & Berger, 1996). The financial problems associated with having no male partner also become more problematic in this area due to the gender inequalities in employment (Cooke & Kim, 2017). However, caution should be used when elucidating the relationship between IPPs and maternal filicide based on cultural differences, as this has also been reported in previous research conducted in Euro-American area. Instead, further endeavors are necessary to determine whether any cultural factors influence filicide involving female perpetrators. Meanwhile, with social factors that could affect our theme, the high suicide rate that has been plaguing South Korea for long time can also be considered. Until 2018, South Korea had the highest suicide rate among the OECD member countries for thirteen consecutive years, and suicide rate is one of the strongest social factors that increases the rate of filicide. Thus, efforts to decrease the suicide rate might contribute to reducing incidences of homicide-filicide in South Korea, which in turn may reduce the rate of child homicide itself. 3 Victim’s age under one vs. others In line with previous literature, in the current study, a child younger than 1 year was also the most at risk for homicide (Alder & Polk, 2001; Daly & Wilson, 1988). Clusters can be divided into victims' main age less than 1 year (Neonaticide, No abuse, Paternal infanticide, and Maternal infanticide) and others (Torture, Maternal filicide, Paternal filicide, Psychotic killings). Cause of death by asphyxiation or drowning is considered relatively less violent and account for a larger proportion in the clusters in which the victim’s age is less than 1. SIDS and UNKNOWN as the cause of death are included in clusters when the age is less than 1, and the intention of homicide is often less obvious (Table 3). In the present study, there were 47 SIDS cases in the 341 autopsy cases, and among them 4 SIDS cases, two clustered in Maternal infanticide and two in No abuse, were found to be at least suspicious child-homicide, which is 8.5 % (4/47) of SIDS. This result of 8.5 % is similar to Levene and Bacon (2004)’s argument that up to 10 % of SIDS cases are, in reality, undetected homicide. Those SIDS cases that were suspicious had the following characteristics. First, with all four cases, the biological mother’s age ranged between 23 and 28, which is a relatively young age to be a mother in South Korea where the average age of first-time mothers is 31.6 years. Second, the caregiver’s obvious failure to provide adequate hygiene, clothing, medical care, and supervision, with confusing and unpredictable care patterns, was observed. For example, in two cases the house was extremely dirty (oil spilt all over the floor, large amount of disorganization, dark rooms, bad smell), and in another case, the child had a skin rash due to poor hygiene. One mother had multiple mental health problems, such as postnatal depression and video game and alcohol addiction, and she played videogames and was drinking while the baby was dying. All of the perpetrators admitted that the environment they had provided could have been hazardous to their baby and the cause of death. 5. Conclusion In sum, the current study presented the characteristics of child homicide cases in South Korea by using a novel person-centered analysis, cluster analysis, using Gower distance, with variables extracted from original case files of autopsy and investigation reports, using both quantitative and qualitative methods. The multifaceted nature of the phenomenon was confirmed, and more specific, detailed risk profiles observed helped our understanding of the nature of child homicide in South Korea. Furthermore, by observing the characteristics of clusters, the influence of a common theme between each cluster, that is, the gender of the perpetrator, victim age, and suicidal tendencies, could be discussed. This study was also more inclusive as we used the legal definition of a criminal offense but a less stringent standard of evidence and included those cases in which children have died from all types of assault and abuse and even cases that were “suspected” to be homicide. Thus, we could include some of the cases that have not come to the attention of child welfare services or have not been handled by the judicial system with its attendant uncertainty and confusion. It is especially important when the cause of death is classified as sudden infant death syndrome (SIDS) or Unknown by autopsy. Since we included some of the undetected cases in the “dark figure” by not adopting the strict legal standard, our results might reflect a broader context and circumstance of the child homicide phenomenon in South Korea. Meanwhile, as our data were archival, we did not have expansive measures of many of the variables, and most are categorical. Hence, the subjective nature of allocation of categories is also our major limitation. The judgments were also often made on limited information as we used the original case files obtained in the early stage of investigation. Therefore, it was difficult to identify the potential motives in some cases. Regardless of these limitations, the profiles derived in this study might be useful in the early stage of investigation and used as a clue in pointing the direction of further investigation. Regarding the analytic strategy we adopted, we hope that our person-centered approach using Gower distance as proximity measure will be a stepping stone toward using more statistical procedures with such archival, original data as it enables handling 14

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mixed data with binomial, continuous, and categorical variables. Using the verbal data (i.e., interview transcripts from the investigation reports), which is a rich source of valuable information, by extracting relevant variables through the coding scheme developed when the performing statistical approach provides more specific, detailed profiles, which can deepen our understanding of complex, heterogeneous phenomena such as child homicide. Declaration of Competing Interest There are no conflicts of interest to declare. Acknowledgments This work was supported by National Forensic Service (NFS2018MED01). Ministry of Interior and Safety, Republic of Korea. References Akay, Ö., & Yüksel, G. (2018). Clustering the mixed panel dataset using Gower’s distance and k-prototypes algorithms. Communications in Statistics-Simulation and Computation, 47(10), 3031–3041. Alder, C., & Polk, K. (2001). Child victims of homicide. Cambridge: Cambridge University Press. Bahk, E. (2019, November 3.). 7-month-old baby found dead in Incheon. Retrieved from https://www.koreatimes.co.kr/www/nation/2019/06/281_269955.html. Beautrais, A. L. (2000). Risk factors for suicide and attempted suicide among young people. The Australian and New Zealand Journal of Psychiatry, 34, 420–436. Beyer, K., Mack, S. M., & Shelton, J. L. (2008). Investigative analysis of neonaticide and exploratory study. Criminal Justice and Behavior, 35(4), 522–535. Biron, D., & Reynald, D. (2016). Developing a revised typology of child homicide. Children Australia, 41(1), 8–15. Bortoli, L. D., Coles, J., & Dolan, M. (2013). A review of maternal neonaticide: A need for further research supporting evidence‐based prevention in Australia. Child Abuse Review, 22(5), 327–339. Bourget, D., & Labelle, A. (1992). Homicide, infanticide, and filicide. Psychiatric Clinics, 15(3), 661–673. Brookman, F., & Nolan, J. (2006). The dark figure of infanticide in England and Wales: Complexities of diagnosis. Journal of Interpersonal Violence, 21(7), 869–889. Cheung, P. T. K. (1986). Maternal filicide in Hong Kong, 1971–85. Medicine, Science, and the Law, 26(3), 185–192. Cooke, F. L., & Kim, S. (2017). Human resource management in Asia in the global context. Routledge handbook of human resource management in Asia. Routledge3–20. D’Orbán, P. T. (1979). Women who kill their children. The British Journal of Psychiatry, 134(6), 560–571. Daly, M., & Wilson, M. I. (1988). Homicide. New York: Aldine de Gruyter. Dawson, M. (2015). Canadian trends in filicide by gender of the accused, 1961–2011. Child Abuse & Neglect, 47, 162–174. Gower, J. (1971). A general coefficient of similarity and some of its properties. Biometrics, 27(4), 857–871. Haapasalo, J., & Petäjä, S. (1999). Mothers who killed or attempted to kill their child: Life circumstances, childhood abuse, and types of killing. Violence and Victims, 14(3), 219–239. Herman-Giddens, M. E., Brown, G., Verbiest, S., Carlson, P. J., Hooten, E. G., Howell, E., et al. (1999). Under ascertainment of child abuse mortality in the United States. Journal of the American Medical Association, 282, 463–467. Hohl, B. C., Wiley, S., Wiebe, D. J., Culyba, A. J., Drake, R., & Branas, C. C. (2017). Association of drug and alcohol use with adolescent firearm homicide at individual, family, and neighborhood levels. JAMA Internal Medicine, 177(3), 317–324. Hwa, H. L., Pan, C. H., Shu, G. M., Chang, C. H., Lee, T. T., & Lee, J. C. I. (2015). Child homicide victims in forensic autopsy in Taiwan: A 10-year retrospective study. Forensic Science International, 257, 413–419. Iga, M. (1996). Cultural aspects of suicide: The case of Japanese oyako shinju (parent–child suicide). Archives of Suicide Research, 2, 87–102. Jenny, C., & Isaac, R. (2006). The relation between child death and child maltreatment. Archives of Diseases in Childhood, 91(3), 265–269. Kaufman, L., & Rousseeuw, P. J. (2005). Finding groups in data: An introduction to cluster analysis (2nd ed.). New York, NY: Wiley. Kim, K. Y., Lai, F. Y., Kim, H. Y., Thai, P. K., Mueller, J. F., & Oh, J. E. (2015). The first application of wastewater-based drug epidemiology in five South Korean cities. The Science of the Total Environment, 524, 440–446. Knox, B. L., Starling, S. P., Feldman, K. W., Kellogg, N. D., Frasier, L. D., & Tiapula, S. L. (2014). Child torture as a form of child abuse. Journal of Child & Adolescent Trauma, 7(1), 37–49. Krischer, M. K., Stone, M. H., Sevecke, K., & Steinmeyer, E. M. (2007). Motives for maternal filicide: Results from a study with female forensic patients. International Journal of Law and Psychiatry, 30(3), 191–200. Lawrence, R. (2004). Understanding fatal assault of children: A typology and explanatory theory. Children and Youth Services Review, 26(9), 837–852. Lee, S. (2014). A study of child abuse death case: Based on the ulsan stepmother case. Health and Social Welfare Review, 35(2), 254–286. Lee, S. J., Perron, B. E., Taylor, C. A., & Guterman, N. B. (2011). Paternal psychosocial characteristics and corporal punishment of their 3-year-old children. Journal of Interpersonal Violence, 26(1), 71–87. https://doi.org/10.1177/0886260510362888. Levene, S., & Bacon, C. J. (2004). Sudden unexpected death and covert homicide in infancy. Archives of Disease in Childhood, 89, 443–447. Liem, M., & Reichelmann, A. (2014). Patterns of multiple family homicide. Homicide Studies, 18(1), 44–58. https://doi.org/10.1177/1088767913511460. Liu, H., Li, J., Wu, Y., & Fu, Y. (2018). Clustering with outlier removal. IEEE transactions on knowledge and data engineering ArXiv preprint, page arXiv:1801.01899. Ma, L., Andersson, G., & Neyer, G. (2014). New patterns in first marriage formation in South Korea. Malmquist, C. P. (2013). Infanticide/neonaticide: The outlier situation in the United States. Aggression and Violent Behavior, 18(3), 399–408. Mariano, T. Y., Chan, H. C., & Myers, W. C. (2014). Toward a more holistic understanding of filicide: A multidisciplinary analysis of 32 years of U.S. arrest data. Forensic Science International, 236, 46–53. https://doi.org/10.1016/j. forsciint.2013.12.019. McKee, A., & Egan, V. (2013). A case series of twenty-one maternal filicides in the UK. Child Abuse & Neglect, 37(10), 753–761. Miller, M., Azrael, D., Hepburn, L., Hemenway, D., & Lippmann, S. J. (2006). The association between changes in household firearm ownership and rates of suicide in the United States, 1981–2002. Injury Prevention, 12(3), 178–182. https://doi.org/10.1136/ip.2005.010850. Parrish, J. W., Schnitzer, P. G., Lanier, P., Shanahan, M. E., Daniels, J. L., & Marshall, S. W. (2017). Classification of maltreatment-related mortality by Child Death Review teams: How reliable are they? Child Abuse & Neglect, 67, 362–370. Paulozzi, L., & Sells, M. (2002). Variation in homicide risk during infancy: United States, 1989–1998. MMWR Weekly, 51, 187–189. Pierce, M. C., Kaczor, K., Acker, D., Webb, T., Brenzel, A., Lorenz, D. J., et al. (2017). History, injury, and psychosocial risk factor commonalities among cases of fatal and near-fatal physical child abuse. Child Abuse & Neglect, 69, 263–277. Porter, T., & Gavin, H. (2010). Infanticide and neonaticide: A review of 40 years of research literature on incidence and causes. Trauma, Violence & Abuse, 11(3), 99–112. Putkonen, H., Amon, S., Eronen, M., Klier, C. M., Almiron, M. P., Cederwall, J. Y., et al. (2011). Gender differences in filicide offense characteristics: A comprehensive register-based study of child murder in two European countries. Child Abuse & Neglect, 35, 319–328. Putkonen, H., Amon, S., Weizmann-Henelius, G., Pankakoski, M., Eronen, M., Almiron, M. P., et al. (2016). Classifying filicide. International Journal of Forensic Mental Health, 15, 198–210. https://doi.org/10.1080/14999013.2016.1152616. Resnick, P. J. (1970). Murder of the newborn: A psychiatric review of neonaticide. The American Journal of Psychiatry, 126(10), 1414–1420.

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Child Abuse & Neglect 101 (2020) 104322

K. Jung, et al.

Roach, J., & Bryant, R. (2015). Child homicide: Generating victim and suspect risk profiles. Journal of Criminal Psychology, 5(3), 201–215. Schnitzer, P. G., Slusher, P. L., Kruse, R. L., & Tarleton, M. M. (2011). Identification of ICD codes suggestive of child maltreatment. Child Abuse & Neglect, 35(1), 3–17. Scott, D. (2018). Reporting fatal neglect in child death review. Trauma, Violence & Abuse. https://doi.org/10.1177/1524838018770416. Sidebotham, P., Bailey, S., Belderson, P., & Brandon, M. (2011). Fatal child maltreatment in England, 2005–2009. Child Abuse & Neglect, 35(4), 299–306. Sidebotham, P., Brandon, M., Bailey, S., Belderson, P., Dodsworth, J., Garstang, J., et al. (2016). Pathways to harm, pathways to protection: A triennial analysis of serious case reviews 2011 to 2014. Department for Education. Spinelli, M. G. (2001). A systematic investigation of 16 cases of neonaticide. The American Journal of Psychiatry, 158(5), 811–813. Statistics Korea, Vital Statistics (2017). Deaths by age and sex: Province. [Internet]. Retrieved from:http://kosis.kr/eng/. Stöckl, H., Dekel, B., Morris-Gehring, A., Watts, C., & Abrahams, N. (2017). Child homicide perpetrators worldwide: A systematic review. BMJ Paediatrics Open, 1(1), https://doi.org/10.1136/bmjpo-2017-000112. Takahashi, Y., & Berger, D. (1996). Cultural dynamics and suicide in Japan. In A. Tn Leenaars, & D. Lester (Eds.). Suicide and the unconscious (pp. 248–258). Northvale: Jason Aronson. Vellut, N., Cook, J. M., & Tursz, A. (2012). Analysis of the relationship between neonaticide and denial of pregnancy using data from judicial files. Child Abuse & Neglect, 36(7-8), 553–563. Wilczynski, A. (1997). Child homicide. London: Oxford University Press. Yasumi, K., & Kageyama, J. (2009). Filicide and fatal abuse in Japan, 1994–2005: Temporal trends and regional distribution. Journal of Forensic and Legal Medicine, 16, 70–75.

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