The Health Department’s findings, compiled in a 2017 draft report, were striking: Though fewer people per capita die at the hands of the police in New York than in almost any other place in the United States, the city was significantly underreporting the deaths. The review also found that the incidence of deaths at the hands of the police was five times higher for black New Yorkers than for whites.

Dr. Bassett’s team identified 105 people killed by the police or police activity during the period from 2010 to 2015, more than double the 46 the agency had publicly reported for those years. Of the unreported deaths, 13 were bystanders hit by police bullets or pedestrians killed from vehicle accidents during police activity. The team also found deep racial disparities in the deaths. For example, six black New Yorkers and five Hispanic residents who died as a result of encounters with the police during this period were unarmed; no unarmed whites were killed.

The findings, which could have changed police practices and saved lives, never saw the light of day.