An empirical study of characteristics and types of homicide-suicides in Hong Kong, 1989-2005

Clinical classification of types of homicide-suicide (HS) was proposed, but no information on empirical-based classification and prevalence of different types of HS was available. This paper aimed to empirically classify HS events into different clusters and to discuss specific evidence-based prevention initiatives.

Data of HS offenders from Coroner's Court were analyzed through a two-step cluster analysis. Number of clusters and appropriate allocations of cases were obtained. External background variables were tested through post hoc tests to explore the differences among clusters.

Two hundred and thirty-one people died in 98 episodes in the study period (1989-2005). The majority of HS offenders were male (n=68, 68.7%) and aged 30-49 (n=62, 62.6%). Domestic killing was the major type of HS in which over 60% of the homicide motivation was related to spousal conflicts or altruistic reasons. Spouses (n=46, 46.5%) and children (n=47, 47.5%) were predominantly the victims. The common killing methods included chopping with weapons (n=33, 33.3%) and charcoal burning (n=22, 22.2%). Six clusters of HS were derived from the cluster analysis and were further reduced to four major classes. Four major classes were dispute, conflicts in a relationship, altruistic, and mental illness. These classes could be differentiated by methods of homicide and suicide, gender of perpetrator, relationship with victim, and indebtedness.

Financial problem, dispute and domestic violence are significant precipitants of HS in Hong Kong. Those people associated with the precipitating factors should be the targets for intervention and prevention.