Attorney General Eric Holder and the Department of Justice are taking notice of what's happening, although some have criticized their response as slow. The evening of 8/13 they briefed President Obama on the situation.
Members of the Congressional Black Caucus, Reps. Marcia Fudge (D - OH 11), John Conyers (D - MI 13), and William Lacy Clay (D - MO 1) wrote a letter dated 8/11 to Atty. General Holder demanding an investigation. Rep. Emanuel Cleaver (D - MO 5) supported them on Twitter on 8/14.
Sen. Claire McCaskill (D - MO) is reportedly also talking with the Justice Department.
On 8/15, the FBI was canvassing Ferguson to find people to interview in the investigation.