Small crowds staged largely peaceful protests late on Wednesday over the fatal shooting of a black teenager by a white police officer in Ferguson, Missouri, the calmest night since riots erupted over the racially charged killing. U.S. Attorney General Eric Holder met the parents of 18-year-old Michael Brown and promised his department would hold a thorough investigation into a case that has reignited a debate over the justice system’s treatment of African Americans. “I am the Attorney General of the United States, but I am also a black man … I can remember being stopped on the New Jersey turnpike on two occasions and accused of speeding.