Attorney General Eric H. Holder Jr. said Thursday that the federal government should collect “better, more accurate data” regarding how many civilians are killed by police and how many officers are killed in the line of duty.

“The troubling reality is that we lack the ability right now to comprehensively track the number of incidents of either uses of force directed at police officers or uses of force by police,” Holder said Thursday morning at a ceremony honoring the Rev. Martin Luther King Jr., according to his prepared remarks. “This strikes many — including me — as unacceptable.”

A series of high-profile police shootings last year, including the deaths of Michael Brown in Missouri and Tamir Rice in Ohio, sparked a wave of protests and revived a debate regarding the way police officers use lethal force. It also drew attention to the fact that the debate was occurring despite the lack of a comprehensive national database documenting every time police officers shot or killed someone.

The FBI keeps track of what are deemed “justifiable homicides” by police officers. In 2013, the FBI reported that there were 461 such deaths at the hands of law enforcement officers. However, as the Justice Department notes, the reporting is not mandatory and not all police departments participate. As a result, journalists and academics who independently study the issue believe the numbers are incomplete and say there are more than 1,000 such deaths each year, the Washington Post  reports.

Holder said Thursday that improving the way this information is collected would simultaneously address concerns people have regarding police officer safety and civil liberties.

Chuck Canterbury, president of the Fraternal Order of Police, has called on Congress to create and fund a program to help agencies collect and submit this data.