The Department of Justice's pilot program to collect data on how many people are shot or killed by police officers each year relies on voluntary participation by state and law enforcement departments, NBC News reported.
Historically, states have typically been reluctant on sharing such information, according to criminal justice experts. And without that data, federal officials don't know how many officers cause injuries through excessive "use-of-force."
Americans "actually have no idea if the number of black people or brown people or white people being shot by police is up, down or sideways over the last three years, five years, 10 years," FBI Director James Comey said recently.
Until recently, it wasn't required that this information be reported to the federal government, and there was no legislation requiring the 18,000 police departments across the nation to keep those statistics. Congress passed the Death in Custody Reporting Act two years ago, but the law still isn't in full effect.