Sworn testimony is evidence given by a witness who has made a commitment to tell the truth.
If the witness is later found to have lied whilst bound by the commitment, they can often be charged with the crime of perjury.
The types of commitment can include oaths, affirmations and promises which are explained in more detail below.
The commitment can come in different forms depending on the situation of the witness.
[13] In United States v. Ward, the Ninth Circuit Court of Appeals ruled that certain other modifications of the oath were acceptable so long as they demonstrated "a moral or ethical sense of right and wrong".