The murder of family members is one of the most difficult crimes to understand. This study uses Shye’s action systems framework combined with multivariate data analysis to test the hypothesis that different forms of familicide will reflect the four states an action system can take, namely: Integrative, Expressive, Conservative and Adaptive. A multidimensional scaling analysis (MDS) was performed on 54 crime scene variables describing 104 cases of intra-familial homicide. The analysis revealed four distinct modes of functioning, which provided tentative support for Shye’s action system. Each of the four modes had distinct associations with perpetrator characteristics. The Expressive and Integrative modes were associated with Cluster B personality traits, and criminal and substance use histories. The Adaptive mode was associated with trauma histories, mood disorders, and personality disorder traits. The Conservative theme was associated with trauma histories and psychotic disorders. Implications of findings for risk assessment and intervention are discussed.