US Attorney General Holder was to visit Ferguson, Missouri
Black leaders' question impartiality of head of investigation who has family ties to the police
Protesters gathered outside the building where a grand jury could begin hearing evidence to determine if a while police officer who shot dead an unarmed black teen should be charged, as US Attorney General Eric Holder made his way to the trouble St Louis suburb of Ferguson.
Outside the St Louis County Justice Centre, where the grand jury was expected to convene, two dozen protesters gathered in a circle for a prayer, chanted, and held signs urging prosecutor Bob McCulloch to step aside. Nearly two dozen officers guarded the main entrance.
Watch: Protesters demand the arrest of cop who killed black teen
McCulloch's deep family connections to police have been cited by some black leaders who question his ability to be impartial in the case of Darren Wilson - the white officer who fatally shot Michael Brown, 18, on August 9. McCulloch's father, mother, brother, uncle and cousin all worked for the St Louis Police Department, and his father was killed while responding to a call involving a black suspect.
The prosecutor, who is white, has insisted his background will have no bearing on the handling of the case. Missouri Governor Jay Nixon said he would not seek McCulloch's removal, citing the "well-established process" by which prosecutors can recuse themselves to make way for a special prosecutor.