[1] The technique involves presenting words, phrases, or pictures containing salient details about a crime on a computer screen, in a series with other, irrelevant stimuli to identify whether the suspect recognizes the crime-related items.
[3] The assumption underpinning the application of BF is that the culprit has concealed information about the crime stored in the brain and it can be revealed by analysing fluctuations in the brainwaves that measure a human's neurological activity.
Brain fingerprinting relies on two major components, specificity and recognition, as it is assumed that the culprit of the crime will recognize certain details of the investigation whilst innocent subjects will not, based on the familiarity of the items presented.
[7] Brain fingerprinting was first used in a criminal case in 1999, when a man named James Grinder confessed to committing a murder that happened 15 years prior.
[9] Following extensive and ongoing research on the brain fingerprinting protocol for detecting deception and its decisive contribution to several trials, the accuracy of technology has been the subject of speculation for a decade.
When carrying out comparative studies between the common polygraph lie detector and brain fingerprinting, the latter appears to have fewer false positives; however, when questioned about specific details, the P300 technique seems to be less reliable.
[16] This controversy is enhanced by discussion surrounding the patent rights and the fraudulent behaviour of the developer Larry Farwell regarding fabricated FBI reports.
[17] Brainwave Sciences, the technology company that owns BF, tainted the validity of the technique when some of its board members became the focal spotlights of scandals in the US.
In 2018, Larry Farwell's technique made a brief appearance in the second season of Netflix's Making a Murderer; however, his findings were not considered during the trial as he was using unauthorized software.