Ferguson protesters demand arrest of officer who shot Michael Brown

"For all," crowd members shouted as the pledge concluded with, "and justice for all."

Michael Brown's family, protesters and civil rights leaders have demanded that Wilson be charged with a crime. They say there is enough evidence for Prosecutor Bob McCulloch to file charges directly without the use of a grand jury and they have demanded that he be replaced with a special prosecutor.

A protest also took place a week ago, at the Ferguson City Council's first meeting since Brown's death on Aug. 9.

Brown, who was black, was fatally shot after a confrontation that began when Wilson asked Brown and a friend to walk on the sidewalk instead of the street. Police have said that Brown and Wilson became involved in a confrontation inside Wilson's squad car. The confrontation then spilled onto the street, where Brown was shot multiple times.

The shooting led to protests and significant unrest in Ferguson and has spurred a national discussion about police treatment of African-Americans.

In addition to a local grand jury investigation, the Justice Department is conducting a wide-ranging civil rights investigation into the practices of the Ferguson Police Department, looking at whether the predominantly white Ferguson police department had a history of discrimination or misuse of force outside the Brown shooting. The department is also conducting a civil rights investigation into the shooting itself.

Critics have called for McCulloch to either step aside or for Gov. Jay Nixon to appoint a special prosecutor, citing concerns about whether McCulloch could fairly oversee the case. McCulloch's father was a police officer killed in the line of duty by a black assailant in the 1960s.

McCulloch, who has been the county's elected prosecutor for more than two decades, could have filed charges himself but chose to take the case to a grand jury. He has said he will present all evidence gathered and let the grand jury decide whether the use of lethal force was justified, rather than make a recommendation.

As expected, the grand jury investigation into Brown's death has gone past the panel's four-month term, which was to expire on Sept. 10. St. Louis County Circuit Judge Carolyn Whittington that day granted an extension until January — the longest allowed by Missouri law.

The extension does not mean the grand jury will meet until January but "just gives them that window," said St. Louis County Court Administrator Paul Fox. He noted that the grand jury is focused strictly on the shooting death of Brown by Wilson and is not considering any other cases.

McCulloch has said previously that the investigation is expected to last into mid-October. A spokesman for McCullough was out of the office this week and didn't respond to calls seeking an update on the status of the investigation.

The grand jury includes six white men, three white women, two black women and one black man. Nine votes are needed to indict.

Wilson remains on paid administrative leave pending the investigations. The name of his attorney has not been made public.

The Associated Press