Something's got to be done to end the killing by white police officers of unarmed African-American men.
The Brown and Garner cases are different. Brown was a suburbanite, Garner a city dweller. One lived in Ferguson, Missouri, the other on Staten Island.
Brown was caught on tape stealing cigarillos; Garner had been warned by police about illegally selling loose cigarettes.
But the only thing that matters is what happened when police confronted the men -- neither of whom was armed.
Brown, we now know, was more than 100 feet away from Police Officer Darren Wilson when the officer fired multiple times -- not 35 feet away, as officials in Missouri initially said. The distance casts doubt on Wilson's story that he feared Brown would overtake him.
But because a local prosecutor gave a grand jury the case -- and because the grand jury acts in secret -- that information did not reach the public until after the panel decided not to charge Wilson.
As for Garner, we saw the video.
And New York Police Department officials said they believed Officer Daniel Pantaleo used an apparent chokehold -- a move that is banned by the department.
Again, a grand jury decided against charges.
In Missouri, there have been allegations that the prosecutor dumped evidence on a grand jury rather than assuming the traditional role of advocating for an indictment.
On Staten Island, some questioned why there was no special prosecutor -- who, unlike the Staten Island district attorney's office, would not have to be concerned about maintaining good relations with the police department.
A question to ask in both cases: Why did both prosecutors rely on grand juries rather than filing charges? The result could have been trials, where witness and expert testimony, evidence and judges' explanation of the law and how it applied would have been public.
The use of grand juries in both cases accomplished little other than to deepen the distrust between African-Americans and police.
Last week, former New York City Mayor Rudy Giuliani said he believed African-American communities had to help defuse that animosity.
But African-American communities want, and need, the kind of policing many white American communities have -- not what's in Ferguson, where police, even after Brown's death, are viewed as an occupying force armed with military equipment.
In New York City, officials were quick after Garner's death -- and a series of other violent incidents involving police -- to announce that police officers would be retrained.
That alone can't re-establish trust, as long as the view that white police officers can kill African-American men with impunity survives.
Which is why it is essential that the U.S. Justice Department investigate the Garner and Brown cases aggressively.
This isn't just about trust with police, it's about trust in the nation's legal system.