Steven Avery was administered a “brain fingerprinting” test during a recent episode of the second season of Making a Murderer. Brain fingerprinting is a technique that uses electroencephalography to determine whether or not specific information is stored in a subject’s brain, and Avery’s defense attorney Kathleen Zellner is pushing for his test to be included as new evidence in his case.
The technique was invented by Seattle neuroscientist Lawrence Farwell and has been used by the FBI, CIA, and US Navy. During the test, information is presented on a computer screen while the brain’s response to the information is measured.
“Brain fingerprinting is a scientific technique for detecting concealed information stored in the brain by measuring brainwaves,” said Farwell, according to Fox News. “We can tell what a person knows or does not know,” said Farwell. “So, we can test if a person knows the details about a murder that would be known only to the perpetrator and investigators.”
According to a 2015 report from The Verge, brain fingerprinting functions like an “advanced lie detector test.” The test takes EEG readings of brain activity using electrodes, then tracks people’s response to specific facts or images in order to determine whether or not those details are stored in their brains.
In 1965, a group of scientists discovered a distinctive surge of electrical activity in the EEG wave when a person saw something familiar, usually arriving 300 milliseconds after the object was revealed. They called it the P300 response, and while the neurological origins of the surge are still unclear, the behavior has been replicated over and over in the decades since.
Brain Fingerprinting has proven to be a highly controversial method of testing, with experts and analysis questioning the validity of its results. However, Zellner believes the test will be useful regarding the allegations against Avery.
Zellner explained: “I’d learned about testing that many authorities think is superior to polygraph, which is Brain Fingerprinting.”
According to Farwell, the issue with brain fingerprinting somebody like Avery, who has already learned most of the crime’s evidence during trial, is that there isn’t a lot of “new information” they can present him to help give an accurate reading.
According to Fox News, in the new motion, Zellner, states that new evidence involving bloodstain analysis was used in a brain fingerprint test of Avery. “The motion states bloodstains show Teresa Halbach was attacked behind her car and the cargo door was open when she was attacked,” Fox reports. Zellner also says that information was never shared with Avery before his test.
The determination computed by the brain fingerprinting system shows that the new information about Halbach’s attack was absent from Avery’s brain with a statistical confidence of 99.9 percent.
“There is no such thing as 100 percent in science, so we say over 99 percent accurate or less than one percent error rate,” said Farwell, according to Fox. However, on his website, Farwell claims that “100 percent of determinations have been correct,” and that the test has made a definite determination in every case, including felony crimes.
Farwell also claims that no one has ever beat a brain fingerprint test, and he is so confident in the test’s accuracy that he is offering $100,000 to anyone that thinks they can. However, there have been several scientists who have attempted to discredit some of Farwell’s work. A 2014 study that claimed that the results of brain fingerprinting were often less reliable than the polygraph.
During Avery’s brain fingerprinting test, Farwell showed him words on a computer screen, some of which were related to Teresa Halbach’s murder and some which were not. “We present three different types of stimuli,” Farwell explains during the second episode of Making A Murderer Part 2. “Things we know he knows, things that are irrelevant, and then probes, where we will get the response only if he knows it.”
The computer flashed words such as “Toyota RAV4,” “golf club,” and “.22 bullet.” At the end of the testing, Farwell claimed he believed Avery wasn’t involved with Halbach’s murder.
Brain fingerprinting isn’t often used in court. However, the test was used in one 2001 murder case, where the man convicted of the crime was eventually exonerated after serving 25 years in prison, Fox News reports.