Several dozen protesters gathered Wednesday outside the St Louis County prosecutor's office, calling for Ferguson police officer Darren Wilson to stand trial for the death of Michael Brown. Inside, a 12-member grand jury began hearing evidence in the case.
Nearby, US Attorney General Eric Holder, on a day trip from Washington, mingled with Ferguson community leaders and residents.
But so deep is the lack of trust among African-Americans in their nation's criminal justice system that many dread the idea that Wilson, 28, a police officer for six years, might get off scot-free.
"I honestly believe this is the beginning of a cover-up," said Jerryl Christmas, a well-known African-American lawyer, amid growing calls for McCulloch -- whom critics say has a track record over two decades in office of not going after police wrongdoing -- to be pulled off the case.
Nationally, "although black men made up only 27.8 percent of all persons arrested from 2003-2009, they made up 31.8 percent of all persons who died in the course of arrest, and the majority of these deaths were homicides," the American Civil Liberties Union has reported.
"It's hard for a community to have confidence in a system that only prosecutes them," said Christmas, a one-time prosecutor and a leader of Wednesday's orderly protest.
Christmas pinned part of the blame on a significant lack of African-Americans in key positions throughout the criminal justice system.
According to a Justice Department report, blacks as well as Hispanics are three times more likely to be searched during a traffic stop than whites, and four times as likely to experience the use of force in encounters with police.
Statistics also indicate that one in three African-American males can expect to spend some time in prison, while black high school students are far more likely to be arrested than white classmates, the liberal Center for American Progress think tank has noted.
Jess Luby, who came down from Minnesota with fellow activists, said she was 23 years old when she was pulled over late one night for alleged careless driving.
She said she spent two years fighting the charges, which were finally dropped last month. "They try to suck you into the system," she told AFP, "and that's why people don't want to fight it."