Give a stream of consciousness and then the final answer. The United States Attorney General (A.G.) is the head of the United States Department of Justice per 28 U.S.C. 503, concerned with legal affairs, and is the chief lawyer of the United States government. Also in cases of the federal death penalty, the power to seek the death penalty rests with the Attorney General.

Answer this question: which department in the presidents cabinet is led by the attorney general?
The important part for answering this question is: The United States Attorney General (A.G.) is the head of the United States Department of Justice per 28 U.S.C. 503, concerned with legal affairs, and is the chief lawyer of the United States government.
So, the final answer is the United States Department of Justice.