FRE Rule 702. Testimony by Expert Witnesses
A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:
(a)the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(b)the testimony is based on sufficient facts or data;
(c)the testimony is the product of reliable principles and methods; and
(d)the expert has reliably applied the principles and methods to the facts of the case.zx
