The FBI 2

To uphold the law through the investigation of violations of federal criminal law; to protect the U.S. from foreign intelligence and terrorist activities; to provide leadership and law enforcement assistance to federal, state, local, and international agencies; and to perform these responsibilities in a manner that is responsive to the needs of the public and is faithful to the constitution of the U.S.: this is the mission of the Federal Bureau of Investigation. …

…and investigate crimes to help prevent future ones. Their motto is Fidelity, Bravery, and Integrity, and I think that each one of those words is justified when it comes to describing the Federal Bureau of Investigation. When the duties of the FBI are stated in the mission it says to perform these duties in a manner that is responsive to the needs of the public and is faithful to the Constitution of the United States.