Title: Applying an expanded definition to incidents of murder-suicide using CalEVDRS Data

Introduction

Many studies have examined incidents of homicide/suicide; however, usually narrow parameters are used to identify these incidents.  We compare the demographics and precipitating circumstances of incidents meeting the narrow definition with those of incidents meeting an expanded definition of homicide/suicide incidents.

Methods

We used 2010 and 2011 Los Angeles County data from the California Electronic Violent Death Reporting System (CalEVDRS).  The narrow definition of homicide/suicide included incidents with at least one homicide and one suicide occurring within 24 hours.  For our broader definition, we also included cases in which the deaths occurred over 24 hours apart, either the homicide(s) or suicide attempt was non-fatal, and incidents where a homicide/attempted homicide was followed by a legal intervention death/injury.  Chi square and Fischer’s exact tests compared demographics and precipitating circumstances between these groups.

Results

Thirty incidents (69 deaths) met the narrow definition of homicide/suicide and an additional 26 incidents (35 deaths) were included using the expanded definition.  Homicides accounted for over half of deaths among both definitions.  Cases meeting the expanded definition were more likely to include Black and younger decedents, but were less likely to involve a firearm.  The role of intimate partner violence in these incidents was not significantly different for the two groups.

Conclusion

While there were significant differences in demographics between the victims of the narrow and expanded definitions of homicide/suicide incidents; the similarities in the role of intimate partner violence suggest the expanded definition may provide useful information about these incidents.