Under Rule 705, how may an expert testify about underlying data?

• A. An expert may testify about the opinion without first testifying to underlying data, but data may be disclosed on cross-examination or upon request.
• B. The data is irrelevant to cross-examination.
• C. The data must be admitted as a court exhibit first.
• D. An expert must disclose underlying data before testifying.

Answer: (A)

Rule 705 lets an expert testify about the opinion and the data or information they relied on without first presenting that underlying data on the stand. The expert can describe the data as the basis for the opinion, but the actual data does not have to be introduced at the time of testimony. Instead, the data may be disclosed to the other side during cross-examination or upon request. This arrangement keeps the trial efficient while still giving the opposing party an opportunity to scrutinize the data by request or during cross-examination. The data does not have to be admitted as a separate court exhibit before the expert testifies.