US V. Semrau (2010/2012)
Definition
The US district court Daubert hearing (2010) and Sixth Circuit affirmance (2012) excluding Cephos fMRI lie-detection evidence on grounds of insufficient testability, absence of a known field error rate, and lack of general acceptance in the cognitive-neuroscience community.
- District court hearing
- 2010, Daubert hearing
- Appellate ruling
- 2012, Sixth Circuit affirmance
- Evidence excluded
- Cephos fMRI lie-detection evidence
- Grounds
- Untested field error rate, no general scientific acceptance
Common questions
Why did the court reject fMRI lie detection despite laboratory studies supporting it?+
The lab studies cited relied on controlled conditions unlike a real interrogation, so the court found no known error rate for real-world use and no consensus in the cognitive-neuroscience community that the technique was ready for courtroom reliance.
Has any US court since admitted fMRI lie-detection evidence at trial?+
No US court has admitted it as substantive lie-detection evidence at trial since Semrau; it remains excluded under Daubert and Frye standards across the jurisdictions that have considered it.
Related terms
- AI Act Article 5(1)(F)
- The EU AI Act prohibition on AI systems that infer emotions, intentions, or characteristics from biometric data in law-enforcement and related contexts....
- BEOS / Brain Fingerprinting
- Lawrence Farwell's EEG-based method using the P300 event-related potential to detect concealed knowledge of crime-relevant items. Addressed by the Indian Supreme Court...
- BOLD Signal
- Blood-oxygen-level-dependent signal; the measure in fMRI that captures changes in the ratio of oxyhaemoglobin to deoxyhaemoglobin as a proxy for neural activity....
- Cephos Corporation
- A US company that offered commercial fMRI lie-detection services from approximately 2006. Its technique was excluded from evidence in US v. Semrau...
- Daubert Standard
- The US federal evidentiary standard (Daubert v. Merrell Dow Pharmaceuticals, 1993) requiring that expert testimony be based on scientifically valid methods with...
- Ecological Validity
- The degree to which a measurement or test procedure produces results that generalise from the controlled laboratory context to the real-world condition...
- Greely-Illes Critique (2007)
- Henry Greely and Judy Illes's 2007 analysis in the American Journal of Law and Medicine identifying five categories of problem with fMRI...
- No Lie MRI
- A San Diego-based company offering fMRI lie-detection services during the same period as Cephos. No court has admitted No Lie MRI evidence...
- P300 ERP
- A positive-going scalp electrical potential peaking approximately 300 ms after presentation of a significant, infrequent, or unexpected stimulus. Used in EEG-based concealed-information...