© D.L. Crumbley
Rule 704 - Opinion on Ultimate Issue
"Testimony in the form of an opinion or inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact."
The ultimate issue is that which is pivotal for the defendant or the plaintiff and determines the outcome.
Rule 705 - Disclosure of Facts or Data Underlying Expert Opinion
"In civil cases, the expert may testify in terms of an opinion or inference and give his reasons therefore without prior disclosure of the underlying facts or data, unless the court rules otherwise. The expert may in any event be required to disclose the underlying facts or data on cross-examination.”
Experts are, generally, allowed to testify about their opinions or give reasons for their opinions without first testifying about the underlying facts or data.
The court may require the expert to disclose the underlying facts or data during cross-examination.