Some Special Agents are Federal Bureau of Investigation (F.B.I.) agents, also known as FEDS, and Treasury Department (T.D.) agents, also known as Tmen. FEDS are responsible for investigating federal crimes, while Tmen investigate financial crimes such as counterfeiting, tax evasion, and money laundering. Both FEDS and Tmen are highly trained law enforcement officers who work to protect the public from criminal activity.