Domestic violence (DV; including intimate partner and family violence) is associated with heightened lethality risks, yet limited research has comprehensively assessed the connection between DV and fatal violence considering both homicides and suicides. Understanding the fatal consequences of DV can point to missed opportunities to support individuals and their families. To assess the proportion of violent deaths that were connected to DV and describe contacts with the legal system or social services prior to each DV-related fatality. This cross-sectional study used quantitative and qualitative data from the National Violent Death Reporting System (NVDRS) for all individuals who died by homicide or suicide in Washington from January 1, 2015, to December 31, 2020. Analyses were conducted from August 1, 2022, to September 30, 2023. A multipronged approach was used to assess DV history using existing NVDRS variables, leveraging data from prior review of NVDRS death narratives, applying a validated natural language processing tool, and linking related deaths. Domestic violence was recorded as yes or no, but the decedent's role in the abusive relationship (ie, experiencing or enacting DV) could not be differentiated. To describe system involvement prior to each death, keyword searching and hand review of NVDRS death narratives were used. A total of 7352 intentional violent deaths (1192 homicides [16.2%]; 6160 suicides [83.8%]) with known circumstances were recorded in Washington during the study period. Of these, 948 deaths (12.9%) were connected to DV (624 [65.8%] among males; mean [SD] age at death, 45.3 [19.2] years), including 588 suicides (62.0%) and 360 homicides (38.0%). For 420 DV-related deaths (44.3%), there was evidence to suggest that the person who died or their intimate partner(s), family, or cohabitants had prior contacts with the legal system or social services. Specifically, 318 records (33.5%) mentioned prior contacts with law enforcement or the criminal legal system (eg, prior 9-1-1 calls, criminal convictions), and 225 (23.7%) described engagement with social services or the civil legal system (eg, civil protection order, divorce, or child custody problems). In this cross-sectional study, 12.9% of violent deaths in Washington were connected to DV. The findings suggest that more resources are needed to support law enforcement, court professionals, and social services specialists to proactively identify and refer families to wraparound supports before the situation can escalate to a fatality.