WASHINGTON — Dramatic videos of deadly law enforcement encounters and the absence of reliable data about how often police use force contribute to a regrettable narrative that “biased police are killing black men at epidemic rates,” FBI Director James Comey says.

That story line has formed amid a lack of comprehensive, national data about how many citizens are killed or injured at the hands of police officers.

Videos of fatal police encounters that capture the public’s attention and are shared broadly across the internet can fuel the perception that “something terrible is being done by the police,” even if the data aren’t there to back it up, Comey said Sunday, speaking in San Diego during a gathering of the International Association of Chiefs of Police.

“It is a narrative driven by video images of real and gut-wrenching misconduct, by images of possible misconduct, by images of perceived misconduct,” Comey said. “It’s a narrative given force by the awesome power of human empathy.”

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,” or if black people are more likely than white people to be shot during police encounters, Comey said.

That narrative creates a wedge between law enforcement and the public, keeping “good officers in their car” and perhaps causing them to think twice before making a certain traffic stop at midnight, Comey said.

“Our officers see the videos. They desperately do not want to be in one. They think about that all the time,” he added.

On the other side of the divide are distrustful community members who stay quiet instead of sharing information with the police after a crime, he said.

“And so into the chasm, into that gap of distrust, fall more dead young black men. In places like Chicago, we know what the chasm looks like and how much pain it causes,” the FBI director said.

The FBI is moving forward with plans for a national database to track information about police use of force, Justice Department officials announced last week.

“We need to collect actual, accurate and complete information about policing in this country so that we have informed debates about things that matter enormously,” Comey said.


Follow Eric Tucker on Twitter at http://www.twitter.com/etuckerAP