How differently do blacks and whites view Ferguson? Here are the numbers.

Polls show that white and black Americans view the Michael Brown case in Ferguson, Mo., through very different lenses. That disparity could play out in the reactions by the two communities after the grand jury releases its decision.

As a grand jury in Missouri nears a decision on whether to prosecute police officer Darren Wilson for the killing of Michael Brown, history suggests the public response will divide along racial lines: Blacks and whites will view the outcome through starkly different lenses.

It’s a part of American culture that has played out numerous times before, from the trial of police officers charged with beating Rodney King to the case against George Zimmerman in the death of black teenager Trayvon Martin.

Officer Wilson shot and killed Mr. Brown, a black 18-year-old, after a mid-day altercation on a street in Ferguson, Mo., Aug. 9.

The grand jury is considering whether to indict Wilson on a charge of murder or manslaughter – or whether to decide that Brown was the aggressor and that Wilson was acting in self-defense.

To many blacks in Ferguson and across the US, the case is an important test of a justice system they view as racially biased – and of a nation where blacks remain much more likely than whites to be poorly schooled, jobless, or in jail.

“I live in one of the poorest ZIP codes in Missouri,” said Ferguson protester Tory Russell in a conference call with reporters this week, adding that fellow African-Americans in the area experience high rates of infant mortality and murder.

“I never heard any of my elected officials declare those things a state of emergency,” said Mr. Russell, who started the group Hands Up United after Brown’s death to seek justice in Ferguson and beyond.

Missouri Gov. Jay Nixon has declared a state of emergency in advance of the grand jury decision, calling up the National Guard amid risks that protests could be accompanied by vandalism or violence.

Public opinion polls suggest that, if the grand jury endorses no indictment against Wilson, black Americans will generally view it as a case of justice denied, while white Americans will generally see it as justice served.

One mid-September poll of St. Louis County residents, for example, found 7 in 10 blacks saying Wilson should be charged with a crime and an equal share of whites saying the opposite. Ferguson, part of the St. Louis metro area, is in the county.

In a broader nationwide survey, taken around the first week of September, 91 percent of blacks said Wilson should be charged, while only 42 percent of whites said that.

Why the wide disparity?

“The story is [probably] one of lived experience,” says Josh Pasek, a University of Michigan sociologist who helped conduct the nationwide survey. “The day-to-day experience … that black Americans have with police and with other institutions leads to a less trusting environment.”

Blacks and whites tend to live in different neighborhoods – often with contrasting profiles when it comes to jobs, incomes, school quality, family structure, and crime.

So when an event such as Brown’s death occurs, whites and blacks start from different perspectives as they combine details from news reports with “with stuff that we have in our heads from our own experiences,” says Pasek, an assistant professor of communications studies.

He notes that his University of Michigan survey of more than 4,000 Americans drew respondents who were somewhat more educated and politically engaged than an average sample of Americans.

Regarding the Ferguson incident, some Americans are inclined to emphasize elements in the news reports that raise doubts about Brown: that video footage released after his death appears to show him stealing from a convenience store minutes before encountering Wilson, that tests show he had used marijuana, and that Wilson has said Brown assaulted him through his car window after he asked Brown to walk on the sidewalk rather than the street.

Others put greater focus on other details attributed to witnesses: that Wilson may have pulled his car aggressively close to Brown and his colleague in the street; that the unarmed Brown, after starting to flee from Wilson’s police car, turned toward Wilson and had his hands raised; and above all that Wilson was firing even when Brown was running away.  

The grand jury has to weigh details such as these – not to mention that witness accounts may differ on whether Brown was moving forward in a way that potentially threatened Wilson when the fatal shots were fired.

And whatever the grand jury decides, Americans will process the news through the filter of how much they trust the judicial system.

Residents of Ferguson, a mostly black community, and others who have joined in Brown-inspired protests across the country, have already been urging President Obama and United States Attorney General Eric Holder for leadership on issues like police and judicial reform.

Activists wield potent statistics: Blacks are far more likely than whites to be stopped by police or arrested. By some estimates, 1 in 3 black males in America will end up in prison at some point in their lives.

In a Gallup survey last year, nearly one-fourth of black men in the 18 to 34 age range said they had been treated unfairly by police in the past month.

Moreover, a ProPublica report, using federal statistics on 1,217 fatal police shootings between 2010 and 2012, found that young black men are 21 times more likely than their white counterparts to be shot dead by police.

On the other side of the race divide, many people in white America, even those who believe blacks often face the negative effects of racism, are wary of prosecuting Wilson.

And in general, whites are more likely to have faith in the institutions of law enforcement and courts.

A 2013 Pew Research Center poll, for instance, asked whether blacks are treated less fairly than whites by the courts. Some 68 percent of blacks said yes, versus just 27 percent of whites who agreed with that view.

An editorial in The Wall Street Journal this week urged Mr. Obama to voice support for the judicial process – in an effort to defuse the possibility of violence after the grand jury results become public.

Citing an FBI report predicting that the grand jury news could result in attacks on police in Ferguson or elsewhere, the Journal said: “Now would be a good time for the President and Attorney General Eric Holder to explain to protesters that a grand jury is part of our criminal justice system, that under that system the accused (including police officers) are presumed innocent, and that a violent reaction will not be tolerated.”

Some academic studies conclude that the high number of black Americans in prison reflects, primarily, higher crime rates in black communities. But racial bias may still be present in various ways, including indirect ones.

“Racial disparities contribute to tension in our nation generally and within communities of color specifically, and tend to breed resentment towards law enforcement that is counterproductive to the goal of reducing crime,” Attorney General Holder said in April, in announcing an effort to curb racial bias in the justice system.

For the protesters like Russell and others, energized in their efforts by Brown’s death, the struggle is about much more than the outcome of a single grand jury.

“We are committed and we will not go away,” said the Rev. Michael McBride of the PICO National Network’s Live Free campaign, who spoke to reporters along with Russell in the conference call this week.