Many legal systems throughout the world protect a person's right against self-incrimination that often results from police questioning or interrogation. This right is known as the right to silence. When the right to silence applies and to whom it applies will differ by jurisdiction.
The idea behind the right to silence is that a person should not be forced to answer questions that may incriminate himself or herself. In some legal systems, the right to refrain from answering questions is explicitly laid down in a constitution or found within the codes or statutes of the country. In other countries, the right has evolved as part of the common law of the country.
In some cases, such as in Germany and the Netherlands, the right to silence applies to a person from the moment he becomes a suspect in a crime. In other countries, for example in India and South Africa, the right does not attach until a person has been accused of a crime. The United States falls somewhere in between the two by attaching the right to silence to anyone considered to be in police custody. Regardless of when the right begins, it generally continues throughout any subsequent judicial proceedings, including trial. In the United States, when a person chooses to exercise his or her right to remain silent at trial it is commonly referred to as "taking the fifth" as the right stems from the Fifth Amendment to the Constitution.
Law enforcement officials, prosecutors, and judges are required to inform a person of his or her right to remain silent in most jurisdictions that recognize the right. In the US, these warnings are known as "Miranda warnings" after the Supreme Court case that required law enforcement officers to give them. In some jurisdictions, exercising the right to remain silent cannot be considered as evidence of guilt, while in others, a judge or jury may infer guilt or wrongdoing from the silence.
The remedy available to a person when his or her right to silence has been violated will also vary by jurisdiction. In most countries, when a person has been questioned in violation of the right to remain silent, any evidence gained from the questioning is inadmissible at trial. If the required warnings have been given and a person chooses to answer questions or cooperate with the police, then he or she is considered to have waived the right to silence. In order to protect any evidence gained by statements that are voluntarily given, most law enforcement agencies have the person sign a waiver or even tape record the warnings and subsequent waiver.