Bureau of Alcohol, Tobacco, Firearms and Explosives
The Bureau of Alcohol, Tobacco, Firearms, and Explosives (abbreviated ATF) is a federal agency inside the Department of Justice. They are charged with the incredibly obvious task of regulating and preventing federal crimes involving alcohol, tobacco, firearms, and explosives/arson. Like their cousins the FBI and local Police, the ATF is a major buzzkill.
The ATF was originally formed during the Prohibition era as a part of the Treasury Department. It was later moved to the Department of Justice and was a division of the FBI. After another very short period of time, it moved back to the Treasury Department. While a division of the Internal Revenue Service as part of the Treasury Department, President Dick Nixon signed an Executive Order making the ATF a Bureau (government offices are ordered in a hierarchy-Department, Bureau, Agency, Office, Commission, Administration, etc.-not in this particular order). Since then, it has been known as the ATF. During the second Bush administration, the ATF was moved into the Justice Department and its mandate was expanded to explosives and arson.
 Role and Functions
ATF special agents have some of the broadest law enforcement authority in the government. They are the only agents of any federal law enforcement agency who are empowered to enforce any statute of federal code. Specifically, ATF special agents have lead investigative authority on any federal crime committed with a firearm or explosive, as well as investigative authority over regulatory referrals and Cigarette smuggling. ATF special agents also often enforce violations of the Uniformed Controlled Substances Act, and have the statutory authority to conduct narcotics cases independently of the Drug Enforcement Administration or any other agency. ATF Special Agents consistently rank at the top or near the top of all federal agencies in cases referred for prosecution, arrests made, and average time per defendant on an annual basis. When they were a division of the IRS they were charged with enforcing and collecting federal taxes on alcohol, firearms, and tobacco, however after their recent more to the Justice Department, the IRS retained this duty.
The ATF is arguably the most selective in hiring compared to its sister agencies. Special Agents must have at minimum a 4 year bachelors degree and 5-6 years of competitive work experience in law enforcement. It is estimated that less than 5% of applicants are eventually hired. Special Agents are also required to pass an extremely rigorous background check to gain, at minimum, top secret clearance. After being fully hired, Special Agents undergo the longest and most extensive training of any federal law enforcement officer.