Under Rule 603, what statement describes the oath requirement for testifying?

• A. A witness must sign a sworn affidavit before testifying.
• B. The oath is administered after the testimony.
• C. Before testifying, a witness shall be presumed to have been sworn in, by an oath or affirmation.
• D. An oath is optional for lay witnesses.

Answer: (C)

Under Rule 603, the key idea is that the oath to tell the truth is treated as a given before testimony begins. The rule says a witness shall be presumed to have been sworn in, by an oath or affirmation, before they testify. That means the courtroom operates on the assumption that the witness is sworn, and the form of that oath can be an oath or an affirmation. You don’t have to prove at every turn that the oath happened; the presumption covers it unless evidence shows the contrary.

This aligns with the statement that before testifying, a witness is presumed to have been sworn in, by an oath or affirmation. The other options don’t fit because they either require an unrelated document (an affidavit) before testifying, place the oath after testimony (which would leave testimony unsworn), or treat the oath as optional for lay witnesses (contrary to the presumptive oath requirement).