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Is fMRI lie-detection evidence admissible?

Talk about cutting edge. Is science on the verge of providing lawyers a usable technology to test the truthfulness of witnesses? 

A Massachusetts forensics firm is currently hawking a lie detection/truth verification service using functional magnetic resonance imaging (fMRI) of the brain.

Creating the technology is one thing. Getting a skeptical judiciary to accept the fruits of that technology is quite another.

On Tuesday, a federal judge in Tennessee issued what appears to be the first thorough treatment of the admissibility of fMRI lie-detection evidence.

That decision illuminates both the current problems with and future promise of fMRI.


Functional magnetic resonance imaging

Dr. Lorne Semrau is in hot water. He’s been indicted for healthcare fraud.

Semrau owns two Tennessee corporations that provide psychiatric services to Medicaid and Medicare patients. According to federal prosecutors, Semrau through those corporations caused $3 million in fraudulent billings to be submitted to the government.

The criminal case against Semrau comes down to one thing: intent.

While prosecutors say Semrau intended to defraud the government, the good doctor contends that he made honest billing mistakes, induced in part by the Byzantine complexity of federal healthcare regulations.

In order to demonstrate that he’s an honest player, Semrau has enlisted the assistance of Dr. Steven Laken and his forensic services firm, Cephos Company located in Tynsboro, Massachusetts.

Cephos is one of two companies currently marketing fMRI lie detection services. (The other is NoLieMRI of La Jolla, Calif.) 

The science is new, backed by less than ten years of development.

Proponents of fMRI claim that they’ve identified the areas of the brain that are most consistently activated by deception. The truthfulness of a particular subject can supposedly be gauged by an analysis of an MRI scan of their brain during the course of targeted questioning.

Laken and his colleagues claim that they are able to identify correctly when subjects are being deceptive with a high level of accuracy, with reported results ranging from 86 to 93 percent accuracy.

To help Semrau’s criminal case, Laken initially scheduled two fMRI-based lie detection tests.  

The first scan indicated that Semrau was telling the truth when he said that he had not intended to defraud the government.

Semrau flunked the second test.

Concluding that fatigue inhibited Semrau’s performance in the second test, Laken scheduled a third.

Wouldn’t you know it, but Semrau passed the third scan with flying colors.

According to Laken, not only did the third test show that Semrau was not deceptive, but based on his prior studies, “a finding such as this is 100 percent accurate in determining truthfulness from a truthful person.”

Atta boy, Semrau!

Now, some might question whether there was a little fishing for the right result here, but Semrau wanted the fMRI results admitted at his trial to bolster his contention that he lacked criminal intent.

And let there be no doubt that Laken and his Cephos firm have a lot at stake here.

It would be a huge boon to the fMRI business to have brain scan results admitted in a federal criminal trial.

Not only would the door be open to fMRI evidence being used in countless other trials, but its admittance would add legitimacy to its application in other contexts, like the workplace.


Daubert analysis

United States Magistrate Judge Tu Pham had first crack at the issue, and Tuesday he weighed in with a thoughtful, comprehensive analysis of whether fMRI-based lie detection met the Daubert standard for the admission of expert scientific evidence.

Applying the first two Daubert factors, Judge Pham was satisfied that fMRI lie detection could be tested and had been subjected to peer review over the past five years.

But the big hurdles were yet to come.

Judge Pham was troubled by the conclusion of a prosecution expert that fMRI is currently not ready to be used in real-world lie detection.

“Because the use of fMRI-based lie detection is still in its early stages of development, standards controlling the real-life application have not yet been established,” the judge wrote. “Without such standards, a court cannot adequately evaluate the reliability of a particular lie detection examination.”

On this issue, the judge concluded that the “absence of real-life error rates and the lack of controlling standards in the industry for real-life exams are negative factors in the analysis of whether fMRI-based lie detection is scientifically valid.”

These factors buttressed the judge’s conclusion that fMRI-based lie detection has not been generally accepted by the scientific community.


Risk of unfair prejudice

After concluding that Semrau’s fMRI evidence was inadmissible under Daubert, the judge doused more water on the prospects for such evidence by concluding that it was inadmissible under Fed. R. Evid. 403.

Likening fMRI evidence to polygraph results, the judge concluded that the danger of unfair prejudice posed by admitting Semrau’s scan results substantially outweighed the probative value of that evidence.

Judge Pham first questioned the fairness of the process by which the results were obtained.

“The examination was conducted without the government’s knowledge and without an opportunity for the government to formulate, submit, or approve the questions asked of Dr. Semrau during the examination,” the judge observed. “Dr. Semrau risked nothing in having the testing performed, and Dr. Laken himself testified that had the results not been favorable to Dr. Semrau, they would have never been released.”

The judge finally questioned the helpfulness of Laken’s conclusions in resolving the ultimate issues in the case.

“Exclusion under Rule 403 is particularly appropriate in this case because, as Dr. Laken testified, although he believes that Dr. Semrau’s responses to the [questions submitted during the test] were truthful ‘overall,’ he cannot offer any opinion as to whether Dr. Semrau was deceptive or truthful as to any specific [question]. …

“Based on his inability to identify which [questions] Dr. Semrau answered truthfully or deceptively, the court fails to see how his testimony can assist the jury in deciding whether Dr. Semrau’s testimony is credible.” (U.S. v. Semrau)

So as far as Pham is concerned, fMRI-based lie detection evidence is inadmissible under the current state of the science.

It remains to be seen whether the U.S. district judge in the case will accept Pham’s recommendation.

In any event, there is enough here for both proponents and detractors of fMRI evidence.

For those opposing its admission, it seems that the scientific community is still some time away from establishing the kind of solid track record that is necessary to satisfy most judges.

For fMRI proponents, Judge Pham’s opinion suggests that current deficiencies in the evidence can be remedied as the science progresses.

Perhaps the biggest question that remains to be answered is whether judges will be able to examine fMRI evidence on its own merits, seeing it as a technology distinct from the long-disparaged polygraph. 

– Pat Murphy


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