On Tuesday night William Murphy, the attorney representing Freddie Gray's family, gave a televised address to an audience in a Baltimore church. As MSNBC cut to his remarks he was reflecting on black America's long experience of police brutality. During slavery, segregation, and the War on Drugs, he argued, police officers have been used to foist immoral laws on young black men. And all along interactions have been fraught with physical abuse.

"That's not my opinion," he said. "That's the verdict of the black community, which has had direct experience that was hidden by coverup after coverup after coverup."

But not anymore.

"You know, they used to be able to get away with lying about it," he explained. "And there were lots of people in the establishment anxious to believe them over anybody black. Thank God for cell phone video cameras. Thank God for cell phone video cameras. Because now the truth is finally coming out. And it's ugly."

How striking to see a black leader express thanks for something as basic as the ability to document abuses that his community has long alleged to a skeptical majority. He knows as well as anyone that video wasn't dispositive in Freddie Gray's killing. He acknowledged that Eric Garner's killing showed its limits too. Nevertheless, he argued that body cameras are a logical next step that could transform the relationship between black people and the police like no other reform.

"We're asking the police to look at their policies," he said. "But we believe that if they have cameras and there is firm control of the on-off switch and harsh penalties for impermissibly turning those cameras off, they will work to increase civility like nothing you've ever seen. We're tired of theoretical solutions and we're desperately looking for practical solutions. And that is a practical solution."

He continued, "Can you imagine if a police officer who was otherwise inclined to be violent knows that his behavior is going to be recorded in intimate detail?"

His ultimate hope, I think, is that the truth will set blacks free now that so many more people will reach judgments based on hard evidence rather than prejudices. Speaking of Baltimore he said, "We live here. We love it here. It's not perfect. It's like being in a bad marriage. But we're not interested in a divorce. We're willing to go into counseling with anybody who wants to make it right."

The offer is more enticing now that anybody can see what's wrong.