CHICAGO — Speaking to a ballroom of thousands of police chiefs and top law enforcement officials, FBI Director James B. Comey said Monday that the national debate over whether the phrase “Black Lives Matter” is anti-cop is further deteriorating  the relationship between police officers and minority communities. And he urged police to embrace the hashtag as an opportunity to better understand those they are sworn to protect.

“There is a line of law enforcement and a line of communities we serve, especially of communities of color…,” Comey said. “Each time somebody interprets hashtag Black Lives Matter as anti-law enforcement, one line moves away. And each time someone interprets hashtag ‘police lives matter’ as anti-black the other line moves away.”

Later in his address, delivered at the International Association of Chiefs of Police annual convention, Comey said that police and the black community need to “get up close, where it is hard to hate” in order to better understand each other.

“Law enforcement can actually use hashtag Black Lives Matter, to see the world through the eyes of people who are not in our line of work and see how they might perceive us,” Comey said. “And I believe that those members of the black community can use hashtag ‘police lives matter’ to see the world through law enforcement eyes and see the heart of law enforcement.”

It was the second time in a week that Comey has publicly addressed the concern held by police chiefs around the nation that the current climate of scrutiny — born in Ferguson, Mo., after the police shooting of Michael Brown and expanded after viral videos such as those showing the detention of Sandra Bland and shooting of Walter Scott — has caused police officers to pull back while on the job.

During both speeches, Comey described the still-weakening relationship between law enforcement and minority communities as two lines that began parallel to one another.

“Each incident that involves real or perceived police misconduct drives one line this way. Each time an officer is attacked in the line of duty, it drives the other line this way. I actually feel the lines continuing to arc away from each other, incident by incident, video by video, more and more quickly,” Comey said, during both speeches. “Just as those lines are arcing away from each other – and maybe because they are arcing away – we have a crisis of violent crime in some of our most vulnerable communities across the country.”

While also raising the possibility that synthetic drugs, lighter sentences for drug crimes, and the availability of drugs could also factor into a spike in crime, Comey said in the speeches on both Friday and Monday that “part of the explanation is a chill wind blowing through American law enforcement over the last year.”

“That wind is surely changing behavior,” Comey said. “Part of that behavior change is to be welcomed, as we continue to have important discussions about police conduct and deescalation and the use of deadly force. Those are essential discussions, and law enforcement will get better as a result. But we can’t lose sight of the fact that there really are bad people standing on the street with guns.  The young men dying on street corners all across this country are not committing suicide or being shot by the cops.  They are being killed, police chiefs tell me, by other young men with guns.”

On Monday, Comey said that he welcomes scrutiny of policing by the Department of Justice — reviews such as those conducted in Ferguson, St. Louis, Cleveland and elsewhere — but noted that the “age of viral videos” has fundamentally changed police work and made officers more hesitant to do the kind of policing that prevents violence.

“We need to figure out what’s happening and deal with it now,” Comey said. “I refuse to wait…these aren’t data points, these are lives.”

Those comments, interpreted by some as a validation of the “Ferguson Effect” — a theory advanced by some that riots and racial unrest in places such as St. Louis and Baltimore have prompted police officers to become more restrained, resulting in upticks in violent crime that otherwise would not have occurred — almost immediately drew skepticism among groups advocating police reform.

“The assertions made by Director Comey are outrageous. By his own admission, these statements are not backed up by data, and there are mixed reports about levels of crime since the heightened scrutiny of police officers began after the protests in Ferguson,” Amnesty International USA executive director Steven W. Hawkins said in a statement. “Rather than making unsubstantiated claims that hinder dialogue and constructive criticism of police practices, what is urgently needed is an official collection and publication of nationwide statistics on the use of force by police.”

On Monday, the White House distanced itself from Comey’s comments.

“The available evidence at this point does not support the notion that law enforcement officers around the country are shying away from fulfilling their responsibilities,” White House press secretary Josh Earnest said on Monday during a press briefing. “The evidence that we’ve seen so far doesn’t support the contention that law enforcement officials are somehow shirking their responsibility.”

Comey’s comments came just weeks after he held a closed-door session with 100 law enforcement and city officials from across the nation, some of whom reported that their officers’ morale was sinking amid ongoing scrutiny of police officers and that their officers were holding back while on the job.

“We have allowed our police department to get fetal, and it is having a direct consequence,” Chicago Mayor Rahm Emanuel declared during the meeting. “They have pulled back from the ability to interdict … they don’t want to be a news story themselves, they don’t want their career ended early, and it’s having an impact.”

But, as Comey himself stressed in the meeting with law enforcement officials, there is no reliable real-time data on crime, making it difficult to parse crime rates and essentially impossible to decipher the reasons for or causes of any recent spikes or drop-offs.

President Obama and Attorney General Loretta Lynch, both of whom will address the IACP conference on Tuesday, have called for better data collection. Obama, speaking Friday on a criminal justice panel at the White House, said that he had ordered a Department of Justice review of current crime rates that concluded that there has been no statistically significant national crime wave post-Ferguson.

“We have seen incredible, historic reductions in crime over the last 20 years. I know that there’s been some talk in the press about spikes that are happening this year relative to last year,” Obama said. “I’ve asked my team to look very carefully at it — Attorney General Lynch has pulled together a task force — and it does look like there are a handful of cities where we’re seeing higher-than-normal spikes. Across the 93 or 95 top cities, it’s very hard to distinguish anything statistically meaningful.”

Aaron Davis contributed to this report.