The phrase taking the fifth is most commonly used in relation to the Fifth Amendment of the United States Constitution. This amendment, designed to protect American citizens from judicial abuse by the government, frequently pertains to the areas of self-incrimination in a criminal or civil trial. The amendment also covers the concept of “double jeopardy” and government appropriation of private property during an eminent domain dispute. The Fifth Amendment reads as follows:
No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a grand jury, except in cases arising in the land or naval forces, or in the militia, when in actual service in time of war or public danger; nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
To protect a trial witness from incriminating himself in matters of criminal or civil liability, he can refuse to answer questions put to him by a judge or attorney. As seen in countless mobster movies and crime dramas, the witness can assert this right by stating that he is “taking the fifth” or “pleading the fifth.” The founders of the U.S. Constitution created the Fifth Amendment, in part, due to their historical awareness that confessions had often been obtained by means of torture. By granting American citizens the right to refuse to answer queries in a court of law, it was hoped that the use of torture would be pointless.
By taking the fifth, a witness is not necessarily helping his case. While the maneuver does protect a person from inadvertently incriminating himself in illegal activity, it may also hamper his ability to defend himself. Judges and juries might also interpret one’s "taking the fifth” as a sign of guilt, indicating that the witness wants to keep information hidden.
There are certain scenarios under which individuals are not allowed to plead the fifth. The Fifth Amendment is not a blanket protection, and in specific areas one can be forced to provide answers or information that will incriminate them in illegal actions. The most common of these is in relation to U.S. tax law. Failing to file a required federal income tax return, or failing to report one’s income, would be a situation in which the government’s need to know supersedes the Fifth Amendment.