Trend of homicide-suicide in Kanagawa Prefecture (Japan): Comparison with western countries.

Abstract

We examined 169 deceased persons and 76 homicide-suicide cases reported in Japan's Kanagawa Prefecture from 1999 to 2011. The relationships between homicide-suicide perpetrators and homicide victims; the numbers of victims; their age, sex, causes and places of death; motivation; and the presence or absence of a suicide note were extracted and examined. The relationship between homicide-suicide perpetrators and homicide victims was examined based on findings from the following: 24 married couples (31%), 22 parents and children aged ≥18 years (29%), 19 parents and children aged ≤17 years (25%), seven families (9%), two couples (3%) and two miscellaneous relationships (3%). The perpetrators comprised 39 men and 40 women, with a mean age of 51.6 years. The victims comprised 39 men and 51 women, with a mean age of 35.4 years. In our study, approximately half of the perpetrators were female, which differed greatly from the reports from Western countries, where most perpetrators were male. Homicide-suicides among married couples accounted for a higher proportion of overall homicide-suicide deaths in Western countries. In Japan, homicide-suicide occurred more frequently with parents and children. Cases in which a mother committed suicide after having killed her young children accounted for a high proportion of these deaths. Because these events occur so frequently in Japan, we recommend making particular efforts to reduce homicide-suicides among mothers and children.