Excluding Brain Scan Lie-Detection Expert Evidence

In a question of first impression, Sixth Circuit affirms the exclusion of brain scan lie detection test results offered by the defense to prove that the defendant lacked the intent to commit healthcare fraud; the expert evidence was independently inadmissable under both FRE 702 and FRE 403, in United States v. Semrau, _ F.3d _ (6th Cir. Sept. 7, 2012) (No. 11-5396)

In a healthcare fraud prosecution, the Sixth Circuit addressed an issue that no court had previously considered. As the circuit noted: “The admissibility of fMRI lie detection testing in a criminal case is an issue of first impression for any jurisdiction in the country, state and federal.” Semrau, _ F.3d at _ (footnote omitted).

In the case, the defendant, president, owner, and chief executive officer of two companies providing psychiatric care, was prosecuted on health fraud charges for fraudulent billing. To support his defense that he lacked the intent to defraud, he offered expert evidence to show that results of a functional magnetic resonance imaging (“fMRI”) lie detector test showed “that found he was generally truthful when, during the test, he said his billing decisions were made in good faith and without an intent to defraud.” Semrau, _ F.3d at _. After a Daubert hearing, United States Magistrate Judge Tu M. Pham recommended that the expert evidence be excluded at trial under both FRE 702 and FRE 403. See . Report-and-Recommendation.pdf Report and Recommendation in United States v. Semrau, No. 07-10074, 2010 WL 6845092 (W.D. Tenn. June 1, 2010). The district court adopted the recommendation. Following his conviction, the defendant challenged the exclusion of the expert fMRI evidence.

Lie Detection Testing Process

The circuit summarized the operation of the brain scan lie detection process:

An fMRI enables researchers to assess brain function in a rapid, non-invasive manner with a high degree of both spatial and temporal accuracy. When undergoing an fMRI scan, a subject lies down on a bed that slides into the center of a donut-shaped magnet core. As the subject remains still, he or she is asked to perform a task while magnetic coils in the scanner receive electric current and the device gathers information about the subject’s Blood Oxygen Level Dependent (“BOLD”) response. By comparing the subject’s BOLD response signals with the control state, small changes in signal intensity are detectable and can provide information about brain activity.

[Further studies and research led to the identification of] the regions of the brain most consistently activated by deception and claimed in several peer-reviewed articles that by analyzing a subject’s brain activity, they were able to identify deception with a high level of accuracy.
Semrau, _ F.3d at _ (citations and quotation marks omitted).

Affirming Exclusion Of Expert Evidence

The Sixth Circuit affirmed the exclusion of the expert testimony under two independent bases. First, the expert evidence was properly excluded under FRE 702. Significant questions remained about whether the lie detection process had been or could be tested. As the circuit noted:

In this case, for example, only [defendant] Dr. Semrau knows whether he was lying when he denied intentional wrongdoing, so there is no way to assess with complete certainty the accuracy of the two results finding he was “not deceptive” (not to mention the one finding that he was deceptive). The same is presumably true for many other “real world” scenarios in which a person may be trying to conceal something which is not already known or easily verifiable.

There was simply no formal research presented at the Daubert hearing demonstrating how the brain might respond to fMRI lie detection testing examining potential deception about real world, long-term conduct occurring several years before testing in which the subject faces extremely dire consequences (such as a prison sentence) if his answers are not believed.
Semrau, _ F.3d at _.

Questions were also raised about the specific tests that were performed. The defendant was older than the subjects tested in the studies. The administered tests “yielded different results.” The expert’s results were based on three tests. The magistrate judge noted that the expert’s “decision to conduct a third test begs the question whether a fourth scan would have revealed [defendant] Dr. Semrau to be deceptive again.” Semrau, _ F.3d at _.

The circuit also questioned whether the expert testimony would be helpful to the jury in deciding the facts of the case. Given the identified “uncertainty from the relevant scientific community as to whether and to what extent the distinctions may, in fact, matter,” it was questionable whether the “jurors, most of whom lack advanced scientific degrees and training, would be poorly suited for resolving these disputes and thus more likely to be confused rather than assisted by” the expert testimony. Semrau, _ F.3d at _.

As an independent basis for exclusion, the circuit agreed that the expert testimony carried a substantial risk of confusion under FRE 403:

We hold that the district court did not abuse its discretion in excluding the fMRI evidence pursuant to Rule 403 in light of (1) the questions surrounding the reliability of fMRI lie detection tests in general and as performed on [defendant] Dr. Semrau, (2) the failure to give the prosecution an opportunity to participate in the testing, and (3) the test result’s inability to corroborate Dr. Semrau’s answers as to the particular offenses for which he was charged.
Semrau, _ F.3d at _.

The novel expert testimony offered in Semrau could not satisfy the standards for expert testimony under FRE 702 and Daubert nor avoid the potential for jury confusion under FRE 403. The case also raises other questions about the role of science to suggest the truthfulness of a defendant or witness. Normally, credibility determinations are left to the fact finder. Courts have generally been reluctant to admit polygraph evidence. See, e.g., First Circuit Renews Criticism Of Polygraph Evidence; see generally Prior Polygraph Blog Posts.


Federal Rules of Evidence