Updated: Dec 13, 2018
The rules on expert witnesses can be found in 702, 703, 704, and 705.
RULE 702 TESTIMONY BY EXPERTS
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
Note:The rule is identical to the federal rule, and to former Rule 43(m)(1), SCRCP, and former Rule 24(a), SCRCrimP.
RULE 703 BASES OF OPINION TESTIMONY BY EXPERTS
The facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence.
Note:The rule is identical to the federal rule and former Rule 43(m)(2), SCRCP, and former Rule 24(b), SCRCrimP. This rule makes it clear that an expert may rely on facts or data in giving an opinion which are not admitted into evidence.
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.
Note:This rule is identical to former Rule 43(m)(3), SCRCP, and former Rule 24(c), SCRCrimP. It is identical to the federal rule as it existed prior the 1984 amendment which added subsection (b) to the rule to prohibit expert testimony on the ultimate issue of whether a criminal defendant is insane.
RULE 705 DISCLOSURE OF FACTS OR DATA UNDERLYING EXPERT OPINION
The expert may testify in terms of opinion or inference and give reasons therefor without first testifying to the underlying facts or data, unless the court requires otherwise. The expert may in any event be required to disclose the underlying facts or data on cross-examination.
Note:The rule is identical to the federal rule. It differs from former Rule 43(m)(4), SCRCP, and former Rule 24(d), SCRCrimP, which contained the phrase "without prior disclosure of" in place of the phrase "without first testifying to."