A disturbing new study reports that half of all people killed by police in 2015 in the United States were severely undercounted. Harvard researchers compiled data from media reports in order to find the misreported police killings, arriving at a harrowing tally of 1,166 fatalities for 2015.

“To effectively address the problem of law enforcement-related deaths, the public needs better data about who is being killed, where, and under what circumstances,” said Justin Feldman, doctoral student at Harvard Chan School and lead author of the study, in a public statement. “But we also found that a different approach — compiling data from media reports — can help solve this problem.”

This is the first study to measure the undercounting of police-related deaths, providing the most accurate count to date. The main issue that prevents us from reliably following police killings is the lack of a nation-wide system that tracks all law-enforcement related fatalities. As such, the Harvard scientists had to turn to two incomplete datasets. One is the U.S. Centers for Disease Control’s National Vital Statistics System (NVSS), which documents fatalities based on state death certificate data. Since 1949, the NVSS features a category called “legal intervention” which coroners can fill under cause of death. The other is a dataset compiled by British media outlet The Guardian called ‘The Counted’ which tallies police killings based on news reports and crowdsourced information.

The media was able to count 93 percent of all police killings. The government barely managed to count half

Researchers looked at the number of people who appeared on The Guardian list only, the NVSS list only, and both lists, then, using statistical tools, ascertained the degree of overlap. They estimate that there were 1,166 law-enforcement related fatalities in 2015.

Some of the key findings from the new study:

• The main reason why police killings were undercounted was due to the coroner failing to mention police involvement on the death certificate.
• There were 599 deaths reported in The Guardian only, 36 reported in the NVSS only, 487 reported in both lists.
• The NVSS documented 44.9% of the total number of deaths and The Counted documented 93.1%.
• Undercounting of police-related deaths varied widely across states. For instance, nearly all of the 17 police-related deaths in Oregon were counted, but none of the 36 such deaths in Oklahoma were
• Misclassification rates for police-related deaths topped 60% among several groups: people under age 18, blacks, people killed by something other than a firearm (particularly Tasers, which accounted for 46 deaths), and people killed in low-income counties.

The authors caution that the nation needs laws requiring police to report all law-enforcement related casualties to public health authorities. The new study also shows that news media reports can be used by state officials to identify police-related fatalities in order to more accurately track such incidents. This shouldn’t be too difficult seeing how a 2014 study of homicides showed that 99 percent were recorded accurately on death certificates. The problem, as such, seems to be unique to law enforcement involvement. Right now, this gross failure to accurately report police killings is unacceptable and, hopefully, the Harvard study will serve as a wake-up call to policymakers.

“As with any public health outcome or exposure, the only way to understand the magnitude of the problem, and whether it is getting better or worse, requires that data be uniformly, validly, and reliably obtained throughout the U.S.,” said Nancy Krieger, professor of social epidemiology at Harvard Chan School and senior author of the study. “Our results show our country is falling short of accurately monitoring deaths due to law enforcement and work is needed to remedy this problem.”

Scientific reference: “Quantifying underreporting of law- enforcement-related deaths in United States vital statistics and news-media-based data sources: A capture-recapture analysis,” Justin M. Feldman, Sofia Gruskin, Brent A. Coull, Nancy Krieger, PLoS Medicine, October 10, 2017, doi: 10.1371/journal.pmed.1002399.

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