Assistant US Attorney (AUSA) is a law enforcement position. The holders are prosecutors of federal crime in the United States of America. They are part of the Department of Justice and answer to the Attorney General. Charles Kenneth Thorogood is the AUSA initially responsible for prosecuting the election fraud case against Atlantic County Treasurer Nucky Thompson when the case is transferred from state to federal court. He is replaced by AUSA Esther Randolph when the Attorney General comes under political pressure to secure a conviction.