Those facing criminal charges aren't required to say anything that could incriminate them. This right is one that is provided by the United States Constitution. You might hear people on crime shows saying that they "plead the Fifth" during testimony.
The Fifth Amendment of the Constitution shields them this way. But what exactly should someone facing criminal charges know about the protection against self-incrimination?
The most important point regarding this right is the protection offered defendants on trial. This is a different right than the right to remain silent when you are being questioned by police officers. During the trial, those on the witness stand can refuse to answer questions about a crime if it will incriminate the witness. This can make it difficult for witnesses to provide information about criminal acts, especially if the witness was a party to the act.
When you exercise your Fifth Amendment right against self-incrimination, you must state that you plead the Fifth. Nothing more has to be said. Your attorney, the judge and the prosecution will be unable to question you further along those lines at trial.
It is important to note that if you are the one who is facing criminal charges, you must plead the Fifth to all questions. You can't pick and choose what questions to answer. This means that if you have things to say that will help your case, you can't give that testimony if you exercise your Fifth Amendment right to avoid self-incrimination.
If you opt to plead the Fifth, the jury is instructed not to take the refusal to answer questions as an admission of guilt. They aren't allowed to consider this point when they deliberate.
Source: FindLaw, "Fifth Amendment Right Against Self-Incrimination," accessed Jan. 18, 2017