Freelance writer Roger Calip profiles West Hartford, CT police polygrapher Paul Melanson in this puff piece for the The Hartford Courant. Excerpt:
West Hartford Police Sgt. Paul Melanson’s detective abilities cover a wide spectrum.
His skills range from the step-by-step deduction required for a field investigation of a kidnapping or homicide to the careful analysis needed to administer a polygraph test.
When he’s investigating a case, “a lot of it is putting together a puzzle that you don’t have all the pieces to,” Melanson said.
When he’s doing a lie-detector test, the puzzle involves what Melanson describes as “an accurate interpretation of the physiological changes that indicate anxiety” and are recorded on a polygraph chart when a person lies.
Melanson’s career accelerated four years ago when he deduced that the department needed a polygraph unit. He recognized that the department’s procedures for processing applicants for police jobs were cumbersome and time-consuming.
State law requires that all applicants get a background check, part of which involves passing a polygraph test. A private polygrapher would administer the test.
Melanson put together a proposal for a polygraph unit at the police station. His superiors accepted the idea, and they created the unit in January 1999.
During the first four months of that year, Melanson trained at the Department of Defense Polygraph Institute in Fort McClellan, Ala.
The training consisted of master’s level courses on anatomy, physiology and psychology, Melanson said, and “after that, it involved instrumentation and test-question construction and administering these tests to actual military recruits.”
Now Melanson not only tests prospective police officers, but also suspects in criminal cases. Here’s how he does it.
After seating a suspect on a plain, gray upholstered chair (which eerily resembles an electric chair), he attaches electrodermal activity plates to one of the person’s fingers; the plates are designed to measure sweat gland activity.
He places a pneumograph tube on the suspect’s abdomen; he puts another on the thoracic cavity. The tubes record upper-body movements and perspiration. Lastly, a cardio cuff is wrapped around the suspect’s arm to record the heart rate and blood flow.
The instruments record bodily changes that occur during questioning, and that can indicate anxiety in the suspect.
“When a person lies,” Melanson said, “there’s a conflict within the brain, and there’s some anxiety with telling the lie.”
The recordings associated with the bodily changes, he said, “are sent to a sensor box, which digitizes the information coming in, and then sends it to the computer.”
Melanson analyzes a chart that is projected onto his computer monitor. When the line on the graph reacts to an answer to a question by shooting upward – creating the highest point, compared with other points on the chart – it indicates “a physiological change that is caused by anxiety about the response,” Melanson said.
“The subject is lying.”
Some people try to fool the device by taking countermeasures that make the polygraph fail to record bodily changes, he said. They breathe in and out heavily or move their upper body, distorting the readings on the chart.
The result, Melanson said, is that no changes in blood flow or heart rate or other physiological activity are picked up. The test ends up being inconclusive.
These days, polygraphers receive training in detecting the countermeasures that some people resort to.
“I can tell by looking at the chart,” Melanson said, “if you’re trying to beat the polygraph.”
Perhaps Sergeant Paul Melanson would be willing to accept Dr. Richardson’s polygraph countermeasure challenge?