To tell the truth

Polygraph tests a valuable resource for police

Polygraph tests a valuable resource for police

March 12, 2004|by PEPPER BALLARD

Liar, liar...

Lie-detector tests have helped the Hagerstown Police Department solve more than 20 cases over the past two years, said Detective Shawn Schultz, who administers the tests at the police department headquarters on Burhans Boulevard.

Although polygraph test results aren't admissible in court, what happens after the test is administered - including admissions that sometimes come during police interrogations - is allowed as evidence.

Defense Attorney John Salvatore said polygraph tests are not admissible in court because the judicial system has determined they are unreliable. But, he said, the technology involved is getting more advanced, so he foresees them being admitted as evidence in the future.


Defense Attorney Lewis Metzner said he doesn't think that will happen in his lifetime.

"They would be a horrible thing to be admissible in a courtroom," he said, adding that the purpose of a trial is for a judge or jury to determine who is telling the truth.

Schultz said the polygraph tests also help get at the truth as an investigative tool.

"The polygraph itself is not to get people in trouble; it's just to get the truth," Schultz said.

Salvatore said he recommends clients not take the polygraph unless they believe they can pass it.

"If, for whatever reason, they don't pass it, then the police are gonna have it out for them," he said.

Metzner said if the state's attorney's office tells him they will drop charges against a client if they pass the polygraph test, he might be more inclined to allow it. He said in some cases it's in the best interest of the defendant to just admit to a crime.

"They're a very good investigative tool, there's no doubt about it," he said.

Aside from using the tests to screen applicants to the police department, police use the test after they've exhausted all other leads in criminal cases, Schultz said. Sometimes testing four or five people who had access to a crime scene, for example, will help police determine if any of them are hiding something.

"We need to find out which one we should be looking at," he said.

A little black chair helps police do just that.

The chair, with pads strapped on the armrests, fitted with a seat pad and a pair of padded footrests, sits in a small room in the corner of the city police criminal investigation unit's office.

When someone sits in the chair, two of their fingers are fitted with grips that measure their sweat, two cords are strapped over their stomach and chest to measure their breathing and one pad is fitted over their arm to measure their blood pressure.

The pads on the chair measure shifts people make while sitting in it.

"Everybody's nervous when they come here," Schultz said.

It's Schultz's job to make sure people coming for the test aren't too nervous to take it. He asks them questions about whether they've had psychological treatment or whether they're under the influence of drugs or alcohol, either of which might alter their response to questions.

Pregnant women cannot be given a polygraph test because police don't want to run the risk the stress would affect the baby, he said.

People are told to get a good night's sleep before they come in for a polygraph, which could take up to three hours.

"If the test is administered correctly, nervousness is factored out," Salvatore said.

After a series of pre-test questions are asked, Schultz goes over questions he plans to ask the person in the hot seat. He does so to make sure they understand his terminology.

The person taking the polygraph test is asked to close his or her eyes to focus, Schultz said.

After the polygraph test, which is made up of about 10 questions, is given once, Schultz gives the person time to rest, then asks the same series of questions. He said he gives the test three times to compare results and to determine what are a person's normal jittery responses and what may be lies.

When a person is told that they've lied, sometimes they break down immediately, Schultz said. Other times, it takes hours.

"I have had many clients confess to a crime after a polygraph interview," attorney Metzner said.

Salvatore said he knows of cases in which the police have told suspects they've failed a polygraph test just to get them to confess. He said he has no problem with that method because sometimes a detective's job involves deceit.

Schultz knows what to look for even without a polygraph.

"You can see in their eyes whether they're lying," Schultz said.

He said he watches for body language that might prompt him into a line of questioning. The way a person moves their eyes to try to recall an event - or, on the other hand, to make one up - can help police make their case.

"If we get the confession, the confession can be used in court," he said.

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