Flawed and unreliable
by Robert A. Waters
William Safire called it “the hit and miss machine.” Even the American Polygraph Association admits to only an 85-89% accuracy rate, with an additional 13% inconclusive. Dan Vergano, of USA Today, wrote that “a 1997 survey of 421 psychologists estimated the test's average validity at about 61%, a little better than chance.”
The polygraph is alleged to measure an individual’s heart rate, pulse, breathing rate, and body temperature. If any of those increase significantly during a question, the suspect is thought to be lying.
The polygraph is so unreliable that the results are not allowed in most American courts, yet cops contend that they rely on it to weed out the innocent and gain confessions from the guilty. The real purpose of the junk science machine is to intimidate suspects into admitting guilt.
Possibly one of the most disturbing facets of polygraphs is that those who administer them seem to believe they can never be fooled. Unfortunately, the criminal justice system is littered with errors in determining who is lying and who is being truthful.
Connecticut pilot Richard Crafts murdered his wife, Helle, and fed her remains through a wood-chipper. He passed two polygraphs before investigators found remnants of her shredded body on the banks of a nearby lake. Crafts was convicted of her murder and sentenced to life in prison.
In Georgia, Fred Tokars passed a polygraph test, but was later convicted of hiring assassins to murder his wife, Sara Ambrusko Tokars.
Serial killer Gary Ridgway, who murdered at least 41 women, passed a polygraph.
Bill Wegerle, whose family was murdered by BTK serial killer Dennis Rader, failed two lie detector tests and was treated as a suspect for many years.
To look at how cops work, and how they use the “lie detector” test, let’s examine the case of Johnia Berry. The beautiful, vivacious 21-year-old from Atlanta attended East Tennessee State University in Knoxville. On the night of December 6, 2004, as she slept in the second bedroom of a friend's apartment, an intruder entered through an unlocked back door and stabbed Johnia 20 times.
He then attacked Jason Aymami, renter of the apartment. Jason was left with eight wounds, including a severe defensive wound on his finger. Aymami eventually fought off the attacker and ran from the apartment to a nearby store where he called police. Johnia also made it out, crawling along the floor and knocking on other apartments for help. No one offered assistance, and she died a short time later.
A fingerprint on a bloody knife found at the scene matched neither Johnia or Jason. Blood covered the wall and floors in Johnia’s room, Jason’s room, the living room, kitchen, hall, and on both the front and rear steps outside the apartment.
Police almost immediately suspected Jason, a conclusion based on their suspicion that this was a “crime of passion.” (Jason and Johnia were not lovers, but investigators concluded that he may have wanted a relationship with her.) So many stab wounds to Johnia showed rage, cops said, and the so-called defensive wound on his finger might have been made when his knife slipped while stabbing his house-mate.
After he got out of the hospital, Jason agreed to take a polygraph. According to investigators, he failed. When confronted, Jason became angry that cops were focusing on him as a suspect. As he vehemently protested his innocence, detectives thought his reaction showed the kind of rage needed to commit a brutal murder.
Even though the fingerprint on the bloody knife didn’t match Jason, and a bloody shoeprint inside the apartment didn’t match his shoes, Jason remained a suspect for nearly two years. He was hounded by police and his name “leaked” to the press, thereby making him a pariah in Knoxville. He eventually moved back to his home state of Colorado.
Finally, in 2007, DNA tests proved conclusively that there was a third person in the room. Investigators matched the samples to Taylor Lee Olson, a convicted burglar who was out on parole. His fingerprints also matched those found on the bloody knife. So much for the crime of passion theory--Olson had no relationship with either Johnia or Jason.
According to his confession, Olson broke into the apartment hoping to find keys to a car parked outside. When Johnia woke up, he stabbed her so she couldn’t identify him. He then attacked Jason when the house-mate opened his bedroom door to check out screams coming from inside the house.
In 2008, Olson hung himself in his jail cell.
After this fiasco, the Knoxville Police Department brought in a group of expert polygraphers to read the results of Aymami’s “failed” test. Several said that the original polygrapher read it wrong.
Whatever the case, it doesn’t speak well of those supposed to be able to divine the truth from a mute machine.
So if I’m ever asked to take a polygraph, my answer will be a big, fat, resounding, “NO!” What about you?