Legal Question in Criminal Law in Tennessee

99.9% of all criminal defense lawyers will tell you "Don't take a polygraph test!"

Well, here I am, in that 0.1% saying "Sure, take a polygraph test, but ...".

Let me explain. No defendant in Tennessee ever got into trouble taking a polygraph test. The fact that he took the test, the results of the test -- pass or fail -- are totally inadmissible in a Tennessee court. The parties cannot even agree to allow the results into evidence.

Q. So how do defendants get in trouble?

A. They get in trouble because of a dirty little secret called the "post-polygraph interview."

That is, the polygraph test is not a scientific, objective test like a ballistics match, or DNA fingerprinting, or even fingerprints examination. In those truly scientific tests, the examiner receives the evidence, conducts the examination, and types up a report. All of the photographs, videos, graphs, etc. are saved for independent review. The examiner never sees the defendant and never questions the defendant (and has no reason to do so).

But a polygraph examination -- at least the ones I have seen conducted by law enforcement by Secret Service agents or other "professionals" -- totally break all the rules for a scientific examination. First of all, there are no video recordings of the pre-test interview, or of the test itself. The defendant will never be given a copy of the graph, or the notes. The polygraph operator physically looks at the subject during the test. The operator makes a "judgment call" whether or not "deception was indicated to relevant questions" (i.e., you failed the test).

Then, the polygraph operator has a "post-polygraph interview" with the defendant in which the operator will attempt to "break the defendant" and get the defendant to admit to the offense alleged. The polygraph operator will use the test results as proof "you are lying to me, now you need to explain to me why ...". There will be no video or audio of the "post-polygraph interview," and if the defendant stumbles into admissions or confessions after denying guilt (but being hounded for a lengthy period of time), the polygraph operator will leave the room and call for a city/county detective. That detective will now turn on the videotape and gleefully record the admissions and confessions, only without any reference whatsoever to the polygraph or the polygraph operator. It is, in short, a scam.

Is there any other true scientific test conducted where the examiner, after finishing the test, calls in the defendant and asks them to "explain these fingerprints, or explain these blood stains?" NO.

In a true scientific test the examiner does the examination, types up his report, and preserves all documentation for subsequent review by other experts.

SO, in a long answer to a short question: Should you take a polygraph test?

Sure, it can't hurt. Nothing you say can be used against you, and the test itself cannot be used against you in any way. If you "pass" (no deception indicated) then the district attorney can't very well prosecute without calling his polygraph operator an incompetent clown. If you "fail" (deception indicated) the district attorney's case isn't any stronger, since that is totally inadmissible at trial (but it might give the district attorney mental incentive to prosecute).

BUT! BUT! Only agree to a polygraph test of the following form:

1 - All proceedings will be videotaped.

2 - You (or your attorney) will receive a copy of the graphs/charts for independent review.

3 - Never agree to any "post-polygraph interview!"

No after-the-fact "maybe you can explain this..." questioning. When the test is over, and you are unplugged from the machine, you get up and walk out.

4 - You (or your attorney) should receive a copy of the typewritten report when the district attorney receives his copy of the report.

By the way, you will never get a district attorney or any polygraph operator I have ever dealt with to agree to the above four terms.