28. Is the bank teller's testimony admissible?

B is correct. Rule 701 of the Federal Rules of Evidence (FRE) allows lay opinion testimony when it is rationally based on the perception of the witness and is helpful to the jury. Here the teller knew the signature of the bank customer on whose account the check was drawn. This knowledge made it possible for her to recognize the signature on the check as a forgery. Her testimony that the signature was a forgery is evidence that the signature on the check presented was different from the signature of the owner of the account (a signature she knows). Obviously the owner of the account would be a stronger prosecution witness than the teller in establishing that the signature was forged, but this doesn't mean that the teller would not be allowed to testify.

A is incorrect. There is no indication that the bank teller is an expert on handwriting, and merely working as a bank teller would not give a person such expertise.

C is incorrect. There is no rule of evidence that would allow exclusion of the testimony on this basis. Moreover, there is no indication that there was fault on the part of the teller.

D is incorrect. Having an expert or even the jury members themselves compare an exemplar established as genuine with the disputed signature is one way to establish whether a signature is forged or authentic. This method of authentication is specifically recognized by Rule 901(b)(3) of the FRE, but it is not the only method authorized. Rule 901(b)(2) also allows authentication by a non-expert on the genuineness of handwriting, so long as familiarity with the handwriting was not acquired for purposes of the litigation.