Polygraph technology has changed with the times

It’s not what you see in the movies

Darrell Cole webcomments@ngnews.ca
Published on May 6, 2014
Sgt. Brian Richardson of the RCMP’s Nova Scotia truth verification section demonstrates polygraph technology with Amherst Rotary Club president and former RCMP officer Paul Calder (centre) and Sgt. Al Carroll of the Cumberland RCMP.
Darrell Cole - Cumberlandnewsnow.com

Sgt. Brian Richardson talked to Amherst Rotarians about the RCMP's truth verification section.

AMHERST – Contrary to what you make see in the movies, taking a polygraph doesn’t involve a smoky room, a large machine, and a police officer using trick questions to break down a suspect.

Speaking to members of the Amherst Rotary Club earlier this week, Sgt. Brian Richardson of the RCMP’s Nova Scotia truth verification unit said the polygraph is just another tool police have at their disposal when investigating a crime.

“There are a lot of misconceptions about how the polygraph works and you sometimes hear about how someone can beat the polygraph when I reality you can’t. If you’re asked a question about a crime and you have first-hand knowledge of that crime it’s going to show,” Richardson said. “The RCMP has been using the polygraph since the early 1970s and it really is very accurate. It’s a very valuable tool to assist in investigations.”

Richardson, who spent several years working as an RCMP officer in Amherst, is one member of a four-person truth verification unit in Nova Scotia. Two officers, including Richardson and the program supervisor, are located in Truro and two are located in Bedford.

The Nova Scotia unit, he added, is also responsible for Prince Edward Island and Nunavut and the four-person team is quite busy doing forensic work, criminal work, statement anaylsis and pre-employment screening for all RCMP candidates.

Members of the truth verification unit also spend time working with police investigators on interview techniques and helping to develop questions that can be asked of a witness or a suspect.

Richardson told Rotarians that polygraph technology has changed a lot over the years from the big box with the moving arms to a digital format that has the data collected by a laptop computer and instead of the analyst sitting at the table reading the moving arms, he could be in another room reading the information on a computer screen.

The polygraph instrument, he said, detects and records physiological features in the body including heart and respiration rates, how much blood the heart is putting out while being tested, sweat gland activity and how much blood is flowing to the extremities during a test.

He said physiological functions will occur involuntarily under stress. By continually monitoring body responses, any changes that occur as a result of questioning can be observed.

“The underlying premise behind the polygraph is a person’s fight or flight reponse,” Richardson said. “As you grow up we are all taught what’s right or wrong. We all make mistakes as we go through life, that’s human nature. Once a person is attached to the polygraph and we start asking questions they know have repercussions you’ll get a different physiological response than you to a question where there are no repercussions.”

A polygraphist can determine if the answers provided are consistent with truthfulness or attempted deception. On rare occasions, Richardson said, the results are inconclusive and the test is later repeated.

“In a lot of cases someone responsible for a crime doesn’t want to take the test because they know their deception will be detected during the polygraph test,” he said. “The majority of the people we interview are truthful.”


Twitter: @ADNdarrell