Stillwater News Press

March 15, 2013

Expert: Polygraphs can exonerate innocent

By Chase Rheam
Stillwater NewsPress

STILLWATER, Okla. — For more than 25 years, Assistant City Attorney Dennis McGrath served on the Oklahoma Board of Polygraph Examiners. Oklahoma Gov. Mary Fallin recently reappointed McGrath to the board, making him the longest serving person on a state-level board or commission.

McGrath, who served with the Stillwater Police Department, was the first officer chosen to go to polygraph school in 1984, he said.

He attended the New York Institute of Security and Polygraph Science. The idea to get involved had not occurred to McGrath previously.

“When I came to work here, I was an investigator and things just went from there,” he said.

However, his training led him to being appointed to the state board in 1986 by Gov. George Nigh.

The process toward becoming a licensed polygraph examiner takes time and hands-on experience, including an 18-month internship and a number of exams.

He said he enjoys the work and its effects.

“I like being able to communicate with people and the challenge it gives in not only identifying perpetrators, but you also get to clear the innocent,” he said.

Administering a test begins with filling out background forms with information including name, history and other pertinent information.

“And then once (the person) completes that, I’ll go through that in a very detailed and organized manner to make sure that I understand that person so I can interpret (them),” McGrath said. “Of course, I need to be able to interpret reactions to the questions. That may be caused by some other outside issue other than the fact that (the person is) guilty.”

There are beliefs that one can trick a polygraph.

“It depends on the qualifications and the skill and the expertise of the examiner,” McGrath said. “When I first went to school, there were people who probably did come up with the wrong results due to a lack of experience.”

However, the more experience a polygraph examiner receives, the more difficult it becomes to attempt.

“If you try to control your reaction by some other physiological trick, it’s going to be obvious what you’re doing,” he said. “I think the CIA and the KGB, if they do it, are probably the only people that can train somebody (to fool) a polygraph.”

As for how the test works into legal proceedings, the admissibility of a polygraph is dependent on each state’s laws.

“There are some states that allow it to be admitted by stipulation of both parties and there’s some states that don’t allow it all,” he said. “And the federal government goes back and forth as to whether it’s admitted or not.”

The exam was even part of some American’s job search more than 28 years ago.

However, the Employee Polygraph Protection Act of 1988 made the practice of using the exams during pre-employment or employment illegal except for certain exemptions. McGrath said he used to conduct many of these exams.

McGrath said the polygraph exam can inform officials as to whether a person should be further investigated or exonerated.

“It’s probably important to the degree that it doesn’t waste a lot of government time in conducting investigations and barking up the wrong tree, so to speak,” he said.

He said polygraphs are used more today than most people might realize.

“Police departments and government agencies can still use them for pre-employment hiring and the longer it’s out there, the more it develops,” he said. “The more it develops, the more it’s going to be accepted into the scientific community.”

And throughout more than two decades, the methods have changed, he said.

“When I started, we used to use an analog instrument of either a four pin or five pin and you had to fill ink wells with ink,” McGrath said.

Due to the test being analog, it was subject to interference from its environment.

“It’s progressed to the point now where telegraphs are computerized,” he said.

“There’s several programs out there, but that’s gone a really long way to stabilizing polygraph examinations in general and trying to perfect them as best as you can.”

McGrath said the process can take time.

“One specific issue exam can take anywhere from two to six hours,” McGrath said. “We have two examiners in our police department — me and another examiner named Heath Hall, and OSU also has an examiner.”

McGrath went on to retire from the Stillwater Police Department. He now serves as the Assistant City Attorney. The news that he had become the longest serving person on a state-level board or commission was news to McGrath.

“I didn’t know that and I never looked at it that way,” he said.

“I just enjoy the interaction between new examiners and old examiners and service to the board and making sure that it maintains its professionalism.”