Brain fingerprinting (BF) is a forensic science technique that uses electroencephalography (EEG)–measured event-related brain potentials to assess whether specific information is stored in a person's memory. The approach was first published in 1991 by Farwell and Donchin and later described by Farwell in a forensic science encyclopedia entry. In a typical test, words or images that contain crime-relevant details are interleaved with neutral items; recognition-related brain responses are compared across item types to infer whether the examinee possesses knowledge of those details.
Courts in the United States have addressed the admissibility of BF evidence. In Harrington v. State (Iowa), the district court ruled the results admissible, and the Iowa Supreme Court later discussed the evidence in the appeal. Legal commentators have analyzed BF's evidentiary status and implications.
Method and P300 response
Brain fingerprinting uses EEG electrodes placed on the scalp to record event-related potentials (ERPs) while the subject views probe (crime-relevant) and irrelevant stimuli. The recognition-related response is used to detect whether information is present in memory; it is not itself a determination of guilt or innocence.
History
Farwell and Donchin's 1991 paper proposed using ERPs for concealed-information detection and reported initial laboratory evidence.
In 2001 the U.S. General Accounting Office (GAO, now the Government Accountability Office) surveyed federal agencies and reported skepticism about prospective operational use, citing limited applicability to federal missions. Academic and legal commentary continued in the early 2000s, including discussions of potential uses and constraints in criminal procedure.
Legal status
In the United States, BF evidence was ruled admissible by an Iowa district court in Harrington v. State; subsequent appellate proceedings in 2003 addressed the case and the evidentiary record. Farwell and colleagues have replied, emphasizing published accuracy claims and test protocols.
Published laboratory and field reports using BF-style ERP measures include claims of high accuracy and low error rates; assessments by other researchers have urged caution and further independent validation before routine forensic adoption. The technique has received periodic media coverage. some authors have proposed future clinical applications of such connectivity-based individual identification.
See also
- Forensic science