## Facts

- Cynette Wilson worked through Corestaff Services L.P., a temporary employment agency, on assignment at an investment bank.
- While on assignment, a bank employee faxed an offensive nude photograph to Wilson’s workstation.
- Wilson reported the incident to both Corestaff and the bank.
- Wilson alleged retaliation for complaining of sexual harassment, relying primarily on coworker Ronald Armstrong.
- Wilson asserted Armstrong would testify that Corestaff manager Edwin Medina told Armstrong not to place Wilson in temporary assignments because she complained of sexual harassment.
- Wilson disclosed an expert, Steven Laken, Ph.D., to testify that Armstrong’s fMRI results showed, to a very high probability, that Armstrong was truthful.

## Issues

1. Whether expert testimony about fMRI-based “lie-detection” results is admissible under New York’s Frye standard to bolster a fact witness’s credibility.
2. Whether such expert testimony should be excluded because it invades the jury’s role in assessing witness credibility.
3. Whether the proponent was entitled to a Frye hearing on admissibility of the proposed fMRI evidence.

## Decision

- The court granted defendants’ motion in limine to preclude expert testimony regarding Armstrong’s fMRI examination and results.
- The court denied plaintiff’s cross-motion seeking a Frye hearing.
- The court held the proposed fMRI lie-detection evidence was inadmissible because it lacked general acceptance and because it would improperly substitute expert opinion for the jury’s credibility determination.

## Legal Principles

- Under Frye, novel scientific evidence is admissible only if the technique has gained general acceptance in the relevant scientific community.
- Trial courts have broad discretion to determine the admissibility and limits of expert testimony.
- Expert testimony offered solely to state that a witness is truthful (or untruthful) is generally inadmissible because credibility assessment is reserved to the trier of fact.
- Even if a technology has accepted uses in other contexts, using it as litigation lie-detection to bolster a specific witness’s testimony may fail Frye and may be excluded as an improper comment on credibility.
- A Frye hearing is not required where the proffer does not show general acceptance for the specific forensic use offered and where the evidence is directed at credibility in a manner that is independently improper.

## Conclusion

The court excluded proposed fMRI lie-detection testimony intended to show a key fact witness was telling the truth, finding the technique not generally accepted for that purpose under Frye and concluding that such evidence would usurp the jury’s exclusive function to evaluate credibility; it also denied a Frye hearing.


Wilson v. Corestaff Servs. L.P., 900 N.Y.S.2d 639 (Sup. Ct. Kings Cnty. 2010)