Caregiving responsibility and the influence of unmarried partners on sentencing for fatal child neglect in Japan: A preliminary investigation

Most child neglect cases in Japan are addressed within the social welfare system rather than criminal courts. However, some fatal cases are prosecuted. This study examined 26 verdicts of fatal child neglect from a Japanese legal database, focusing on unmarried partner (UP) involvement. Nominal clustering analysis classified mothers into three groups: violence, abandonment, and contrast. Bayesian t-tests showed that mothers in the violence cluster—those who failed to prevent UP assaults—received significantly longer imprisonment terms than mothers without a UP. By contrast, the abandonment cluster did not significantly differ from the others. These findings suggest that Japanese courts impose harsher penalties on failed-to-protect (FTP) mothers, underscoring the importance of considering relational factors in sentencing and in preventive interventions.