Whether expert evidence based on or involving physics and related sciences is sufficiently reliable to satisfy the requirements of Federal Rule of Evidence 702 or comparable State rules for the admissibility of expert evidence

McDonough v. City of Quincy, 452 F.3d 8, 21 (1st Cir. 2006) (holding, in plaintiff police officer's unlawful retaliation action against defendant city, that the trial court properly admitted the out-of-court statements....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. Arroyo, 406 F.3d 881, 887-888 (7th Cir. 2005) (upholding trial court's exclusion of the memo prepared by the IRS agent because the information did not establish the reputation of defendant's character....There is a hearsay exception for reputation of a person's character among associates or in the community.

Cf. O'Brien v. Marshall, 453 F.3d 13, 19 (1st Cir. 2006) (holding, in a habeas corpus petition, that the "[petitioner] was not denied the use of compulsory process, but, as with the Fifth Amendment," because the....The Due Process and Compulsory Process guarantees give a defendant in a federal or state criminal trial the constitutional right, not only to compel the attendance of defense witnesses, but also to introduce trustworthy hearsay evidence that is critical or important to the defendant's defense.