NEW : Attorney General urges police to investigate Ferguson . Wednesday : Grand jury could begin hearing testimony Wednesday . Protests over the Brown shooting are likely to continue . The FBI investigates whether police violated the civil rights of Brown , a black teenager .
NEW : Attorney General Eric Holder to visit Ferguson . NEW : Grand jury could begin hearing testimony Wednesday . Protests over Michael Brown case are likely to continue . The FBI investigates whether police violated the civil rights of Brown , a black teenager .