Quantifying underreporting of law-enforcement-related deaths in United States vital statistics and news-media-based data sources: A capture–recapture analysis

Abstract

Background

Prior research suggests that United States governmental sources documenting the number of law-enforcement-related deaths (i.e., fatalities due to injuries inflicted by law enforcement officers) undercount these incidents. The National Vital Statistics System (NVSS), administered by the federal government and based on state death certificate data, identifies such deaths by assigning them diagnostic codes corresponding to “legal intervention” in accordance with the International Classification of Diseases–10th Revision (ICD-10). Newer, nongovernmental databases track law-enforcement-related deaths by compiling news media reports and provide an opportunity to assess the magnitude and determinants of suspected NVSS underreporting. Our a priori hypotheses were that underreporting by the NVSS would exceed that by the news media sources, and that underreporting rates would be higher for decedents of color versus white, decedents in lower versus higher income counties, decedents killed by non-firearm (e.g., Taser) versus firearm mechanisms, and deaths recorded by a medical examiner versus coroner.

Methods and findings

We created a new US-wide dataset by matching cases reported in a nongovernmental, news-media-based dataset produced by the newspaper The Guardian, The Counted, to identifiable NVSS mortality records for 2015. We conducted 2 main analyses for this cross-sectional study: (1) an estimate of the total number of deaths and the proportion unreported by each source using capture–recapture analysis and (2) an assessment of correlates of underreporting of law-enforcement-related deaths (demographic characteristics of the decedent, mechanism of death, death investigator type [medical examiner versus coroner], county median income, and county urbanicity) in the NVSS using multilevel logistic regression. We estimated that the total number of law-enforcement-related deaths in 2015 was 1,166 (95% CI: 1,153, 1,184). There were 599 deaths reported in The Counted only, 36 reported in the NVSS only, 487 reported in both lists, and an estimated 44 (95% CI: 31, 62) not reported in either source. The NVSS documented 44.9% (95% CI: 44.2%, 45.4%) of the total number of deaths, and The Counted documented 93.1% (95% CI: 91.7%, 94.2%). In a multivariable mixed-effects logistic model that controlled for all individual- and county-level covariates, decedents injured by non-firearm mechanisms had higher odds of underreporting in the NVSS than those injured by firearms (odds ratio [OR]: 68.2; 95% CI: 15.7, 297.5; p < 0.01), and underreporting was also more likely outside of the highest-income-quintile counties (OR for the lowest versus highest income quintile: 10.1; 95% CI: 2.4, 42.8; p < 0.01). There was no statistically significant difference in the odds of underreporting in the NVSS for deaths certified by coroners compared to medical examiners, and the odds of underreporting did not vary by race/ethnicity. One limitation of our analyses is that we were unable to examine the characteristics of cases that were unreported in The Counted.

Conclusions

The media-based source, The Counted, reported a considerably higher proportion of law-enforcement-related deaths than the NVSS, which failed to report a majority of these incidents. For the NVSS, rates of underreporting were higher in lower income counties and for decedents killed by non-firearm mechanisms. There was no evidence suggesting that underreporting varied by death investigator type (medical examiner versus coroner) or race/ethnicity.

Abstract

In this capture-recapture analysis, Justin Feldman, of Harvard University, and colleagues find that law enforcement-related deaths in the United States are undercounted in official government data derived from state death certificates compared to news media-based data sources.

Author summary

Why was this study done?

• Several governmental and nongovernmental databases track the number of law-enforcement-related deaths in the US, but all are likely to undercount these deaths.

• To our knowledge, our study is the first to estimate the proportion of law-enforcement-related deaths properly captured by 2 data sources: official US mortality data, derived from death certificates, and The Counted, a nongovernmental database derived from news media reports.

• US mortality data include virtually all deaths that occur in the country, and law-enforcement-related deaths are supposed to be assigned a diagnostic code corresponding to “legal intervention.” If a death is improperly assigned another code, it is considered to be misclassified, which leads to undercounting of the number of law-enforcement-related deaths. We investigated the extent of misclassification and the factors associated with misclassification.

What did the researchers do and find?

• We estimated that 1,166 law-enforcement-related deaths occurred in the US in 2015; The Counted captured a larger proportion of these deaths than the US mortality data.

• Law-enforcement-related deaths were most likely to be misclassified in mortality data if the death was not due to a gunshot wound or if it occurred in a low-income county.

What do these findings mean?

• Datasets based on news media reports may offer higher-quality information on law-enforcement-related deaths than mortality data.

• Further exploration into the ways in which policymakers and public health officials report law-enforcement-related deaths is warranted.