Is there a social worker-client privilege?

Fed. R. Evid. 902(10) ("Any signature, document, or other matter declared by Act of Congress to be presumptively or prima facie genuine or authentic.").Federal Rule of Evidence of 902(10) and comparable State rules provide that any signature, document, or other matter is self-authenticating -- i.e., requires no further evidence of authenticity to be admissible in evidence -- if an applicable statute provides that the signature, document, or other matter is presumptively authentic or if an applicable statute provides that the signature, document, or other matter is prima facie evidence of its own authenticity.

Fed. R. Evid. 804(b)(1) advisory committee's note ("As a further assurance of fairness in thrusting upon a party the prior handling of the witness, the common law also insisted upon identity of parties, deviating only to the extent of allowing substitution of successors in a narrowly construed privity. Mutuality as an aspect of identity is...The hearsay exception for prior testimony can apply in a criminal trial or proceeding against a defendant even if the prosecuting party and offeror in the prior trial or proceeding was a different party and offeror (e.g., a different governmental unit).

Presley v. Lakewood Engineering and Mfg. Co., 553 F.3d 638, 643 (8th Cir. 2009) (plaintiffs offered testimony of "a fire expert and electrical engineer, to investigate the cause of the fire and formulate a theory of fire causation"; the....Some fire reconstruction evidence is insufficiently scientific and insufficiently reliable to pass muster under the requirements of Federal Rule of Evidence 702 or comparable State rules for the admissibility of scientific evidence.