Patterns and Trends Among Intimate Partner Homicide Cases: An Analysis By Sex and Race/Ethnicity

Background. Data suggest sex and racial/ethnic disparities in intimate partner homicide (IPH). Women experience a higher rate of IPH, with Black/African American (AA) and American Indian/Alaska Native (AI/AN) women linked to higher overall homicide rates than White women Additionally, there are differences in trends of IPH rates over time by sex and racial/ethnic groups. For example, the decline in the IPH rate is sharper for men and flatter for women. This suggests a potential need for differences in targets for prevention and the importance to understand these disparities. This study examined two research questions: (RQ1) What are the patterns among IPH cases and their associations with victim’s sex and race/ethnicity? (RQ2) How are state policies associated with the IPH rate, particularly the sex- and race-specific IPH rate?

Methods. The analyses were conducted using the National Violent Death Reporting System, Restricted Access Database (NVDRS-RAD). Data were linked to Census and policy data using the geographic indicator (victim’s residence county and state) in the NVDRS-RAD. The policy variables examined in this study included: domestic violence arrest policies (discretionary/preferred/mandatory), firearm restriction laws, and welfare benefits. Latent class analysis (LCA) and mixed-effects modeling were performed to identify patterns of case characteristics of IPHs and to investigate the differential impacts of policies on subgroups over time. In total, 5,771 IPHs (n = 4,530 female IPHs; n = 1,241 male IPHs) across 16 states from 2005 to 2017 (13 years) were analyzed.

Results. RQ1: The results of LCA suggested a 2-class model for male IPHs and a 3-class model for female IPHs. Classes identified for male IPHs were (a) Physical Fight and Substance Use (17%) and (b) Justice-Involved (83%). Classes identified for female IPHs were (a) Multiple Homicides Followed by Suicides (21%), (b) History of IPV and Substance Use (20%), and (c) Justice-Involved (59%). Significant differences in victim’s race/ethnicity and age by class were found. White women were more likely to be in the Multiple Homicides Followed by Suicides class, whereas Black/AA women were more likely to be in the Justice-Involved class. The percentage of victims included in other race/ethnicity (e.g., AI/AN, Asian) and multiracial were highest in the History of IPV and Substance Use class. RQ2: The descriptive analyses showed that minority groups—particularly multiracial, Black/AA, and AI/AN—had higher IPH rates. Results of mixed-effects modeling suggested distinct state demographic factors related to IPH rate by victims’ sex and race/ethnicity. Most policy variables became non-significant in multivariate models, however bivariate analyses indicated that while mandatory arrest appeared protective for White victims, the same was not true for victims who belonged to a minority group.

Discussion. Overall, findings indicate the importance of analyzing IPH patterns and trends through an intersectional lens. The findings offer some quantitative evidence supporting narratives regarding the disproportionately negative effects of mandatory arrest policy for people of color. Results also indicate the complexity of how various system contacts and risk factors are associated with differing typologies of IPH. The possible variation in preventive strategies by IPH pattern is discussed.