“In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsory process for obtaining witnesses in his favor, and to have the Assistance of Counsel for his defense.” Sixth Amendment US Constitution. 

In many cases the government may try to deny your right to confront witnesses. You and your attorney should at all times advocate the right to confront the witnesses against you. 

The Supreme Court has emphasized this in a landmark majority opinion in Crawford v. Washington (2004), where Justice Scalia rejected the idea that courts could allow out-of-court statements merely because they seemed "reliable." Instead, Scalia held that if a statement is testimonial, the accused must have an opportunity to cross-examine the declarant in court unless that person is unavailable and the defendant had a prior chance to cross-examine them.

He considered this right non-negotiable, rooted in historical practice and essential to preserving the adversarial nature of the justice system.