WASHINGTON –

WASHINGTON (AP) — Attorney General William Barr sought on Thursday to quell tensions over the death of George Floyd in police custody, acknowledging a divide between many black Americans and the police and promising to spare no resource as the Justice Department investigates whether a federal civil rights crime was committed.

“While the vast majority of police officers do their job bravely and righteously, it is undeniable that many African Americans lack confidence in our American criminal justice system,” Barr said at a news conference. “This must change. Our constitution mandates equal protection of the laws and nothing less is acceptable.”

Barr’s comments appeared to contrast with prior statements he’s made condemning protests against the police and what he’s described as a “disturbing pattern of cynicism and disrespect shown toward law enforcement.” But he insisted Thursday that his views have been consistent and that the overwhelming majority of police officers “try conscientiously to use appropriate and reasonable force.”

Throughout his tenure, Barr has similarly been a staunch advocate of police officers. But he vowed that the Justice Department would do its part to investigate and prosecute civil rights crimes.

“I believe that police chiefs and law enforcement officials and leaders around the country are committed to ensuring that racism plays no part in law enforcement, and that everyone receives equal protection of the laws,” Barr said.

President Donald Trump has called Floyd’s killing a “terrible, terrible thing that happened” and called on the Justice Department to expedite its investigation of his death. But he’s steered clear of any mention of how Floyd’s death -- and subsequent unrest around the nation -- fits into the long-stemmed problem of racial bias in policing.

Most of the protesters have been peaceful and tried to discourage violence. Trump, Barr and others lay some of the blame for the unrest on left-wing extremist groups, including antifa, and other “anarchists.” Short for anti-fascists, antifa is an umbrella term for far-left-leaning militant groups that resist neo-Nazis and white supremacists at demonstrations. He also said “foreign actors” appeared to be trying to “play all sides” to further incite violence in the U.S.

“We have seen evidence that antifa and other similar extremist groups as well as actors of a variety of different political persuasions have been involving in instigating and participating in violent activity,” Barr said.

A senior Justice Department official said there have been “multiple instances” where people who have been arrested at demonstrations around the U.S. have identified themselves to law enforcement as members of antifa, the official said. The official, who could not discuss ongoing investigations publicly and spoke on condition of anonymity, did not provide specific details about those incidents.

Federal prosecutors announced Wednesday that three Nevada men with ties to a loose movement of right-wing extremists advocating the overthrow of the U.S. government had been arrested on terrorism-related charges in what authorities described as a conspiracy to spark violence during recent protests in Las Vegas.

Federal agents have made 51 riot-related arrests, Barr said, and 114 law enforcement officers have been injured in protests in Washington.

Asked this week during an interview with former White House press secretary Sean Spicer what else he could be doing to help the nation heal, Trump responded by tallying past efforts his administration has made that have benefited the African-American community.

“We had the best black unemployment rate in the history of our country,” Trump told Spicer in the interview for the conservative cable outlet Newsmax. “More home ownership, more everything, in every way African Americans were in better shape than they ever were.”

White House press secretary Kayleigh McEnany earlier had sidestepped questions about whether Trump believes there’s a systemic bias in American law enforcement against African Americans.

She noted that Trump has spoken out about the treatment by police of Sandra Bland before she was found hung in a Waller County, Texas, jail in 2015 and the February killing of Ahmaud Arberry in Georgia. Former police officer Gregory McMichael, 64, and his son Travis McMichael, 34, have been charged with murder and aggravated assault in the Arberry killing.

But pressed about whether Trump believes there is a larger problem of racial bias in law enforcement, McEnany only acknowledged that Trump “believes there are some examples of injustices.”