Does the FBI investigate all Federal Crimes?

The FBI does not investigate all federal crimes, which makes the correct choice "No." The FBI's jurisdiction is defined by specific areas of law enforcement where it has the authority and expertise. While the FBI handles a wide range of serious federal offenses, such as terrorism, cybercrime, organized crime, public corruption, civil rights violations, and more, there are many federal crimes that local or state law enforcement agencies, or other federal agencies, investigate instead.

Certain federal units, like the Drug Enforcement Administration (DEA), focus exclusively on drug-related offenses, and other specialized agencies are responsible for crimes within their jurisdiction, such as the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) or the Secret Service for financial crimes and protecting the president. Hence, not all federal crimes fall under the purview of the FBI, which highlights the necessity of collaboration among various law enforcement agencies at different levels to effectively address federal offenses.