Expert evidence based on or involving medical science is often sufficiently scientific and reliable to satisfy the requirements for admissibility under Federal Rule of Evidence 702 or comparable State rules.

Abuan v. Level 3 Communications, Inc., 353 F.3d 1158, 1171 (10th Cir. 2003) (holding, in plaintiff employee's employment discrimination action against defendant employer, that the trial court properly admitted testimony of witness on....A statement by an agent or an employee who is not authorized to speak on behalf of the agent's principal or the employee's employer may nonetheless be treated as the statement of the principal or the employer and thus as a vicarious admission that is exempt from the prohibition against hearsay; but such a statement can be imputed to the principal or the employer only if the statement, if by an agent, is about a matter within the scope of the agent's agency or, if by an employee, the statement is about a matter within the scope of the employee's employment.

Cf. United States v. May, 622 F.2d 1000, 1007 (9th Cir. 1980) (upholding trial court's admission of the Apprehension Data Cards with defendants' photographs because such photograph of the person described, as a component....Not every human utterance is capable of amounting to hearsay. Only an utterance that contains an assertion can amount to a "statement" for purposes of Federal Rule of Evidence 801(a) or hearsay under Federal Rule of Evidence 801(c).

United States v. Larson, 112 F.3d 600, 604 (2d Cir. 1997) (upholding trial court's admission of witness's testimony about accused's prior criminal sexual conduct with another minor because it was relevant as there was similarity of the events between the prior criminal sexual conduct and the offense...Applicable federal or state law determines who is a "child" for purposes of Federal Rule of Evidence or comparable state rules that authorize the use of other instances of child molestation or child sex abuse against criminal defendants who are on trial for child molestation or child sexual abuse.