# Police Tactics **URL:** \ **Category:** Factual Questions\ **Created:** [November 13, 2010, 2:29pm UTC](https://boards.straightdope.com/t/police-tactics/560555 "2010-11-13T14:29:09Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![daddyb](https://avatars.discourse-cdn.com/v4/letter/d/5fc32e/32.png) [@daddyb](https://boards.straightdope.com/u/daddyb)\ **Post date:** [November 13, 2010, 2:29pm UTC](https://boards.straightdope.com/t/police-tactics/560555/1 "2010-11-13T14:29:09Z")
Are Police allowed to lie about the results of a lie detector test? ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [November 13, 2010, 2:32pm UTC](https://boards.straightdope.com/t/police-tactics/560555/2 "2010-11-13T14:32:09Z")
Not a lawyer but as I understand it they can lie to a suspect but not in court or probably when providing results to the defense attorney. Wrong forum. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [November 13, 2010, 2:55pm UTC](https://boards.straightdope.com/t/police-tactics/560555/3 "2010-11-13T14:55:53Z")
Welcome to the SDMB, **daddyb**. We’ve organized the place with different forums for different kinds of discussions; you can see descriptions of the various forums [here](http://boards.straightdope.com/sdmb/forumdisplay.php?f=15). I’ve moved your thread from ATMB to General Questions, where we pose questions with factual answers. I trust someone will be along soon to respond to your question. Again, welcome to the SDMB. **twickster** , moderator ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [November 13, 2010, 7:06pm UTC](https://boards.straightdope.com/t/police-tactics/560555/4 "2010-11-13T19:06:15Z")
I believe **runner pat** is correct - it is legal for the police to march into the holding room where you are being held and announce “the lie detector test you took proves beyond a shadow of a doubt that you are guilty. If you want to confess now, we can consider a deal.” If you then confess, it is admissible in court even if the tests showed nothing of the kind. Regards, Shodan ---
**Author:** ![bleibtreu](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bleibtreu](https://boards.straightdope.com/u/bleibtreu)\ **Post date:** [November 14, 2010, 7:46pm UTC](https://boards.straightdope.com/t/police-tactics/560555/5 "2010-11-14T19:46:31Z")
> [@Shodan](#): > > If you then confess, it is admissible in court even if the tests showed nothing of the kind. A confession made under duress or through deception in fact might be excluded in trial. If it is ruled admissible, it’s likely that the fact that the interrogators lied to the suspect about the test result would also be allowed to be presented. It’d be up to the trial judge, and would hinge in part on precedent and case law in the jurisdiction. And, of course, subject to appeal if there’s a conviction. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [November 14, 2010, 7:57pm UTC](https://boards.straightdope.com/t/police-tactics/560555/6 "2010-11-14T19:57:53Z")
I’m not a lawyer. The lie detector (polygraph) is still not admissible as evidence in court. One reason for that is that the results are the interpretation by the person administering the test. ---
**Author:** ![Rachellelogram](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rachellelogram/32/8689_2.png) [@Rachellelogram](https://boards.straightdope.com/u/Rachellelogram)\ **Post date:** [November 15, 2010, 11:47pm UTC](https://boards.straightdope.com/t/police-tactics/560555/7 "2010-11-15T23:47:33Z")
> [@AskNott](#): > > I’m not a lawyer. > > The lie detector (polygraph) is still not admissible as evidence in court. One reason for that is that the results are the interpretation by the person administering the test. Right, but how many people taken into custody are aware that the evidence from lie detectors is not admissible in court? If someone doesn’t know that, and is told that it can be used in court, they may squeal like a piglet. In which case, boom–evidence. All very good reasons not to say a goddamn word under interrogation without a lawyer present. Except of course for the phrase “I’d like to speak with a lawyer.” Repeated over and over again until the cops get tired of asking you questions. IANAL; however, there are cases where cops lie about things in order to obtain information and the lie does not bar admissibility of obtained evidence. Like when infiltrating undercover prostitution or drug rings. ---
**Author:** ![Lakai](https://avatars.discourse-cdn.com/v4/letter/l/9de0a6/32.png) [@Lakai](https://boards.straightdope.com/u/Lakai)\ **Post date:** [November 16, 2010, 12:19am UTC](https://boards.straightdope.com/t/police-tactics/560555/8 "2010-11-16T00:19:06Z")
> [@bleibtreu](#): > > A confession made under duress or through deception in fact might be excluded in trial. If it is ruled admissible, it’s likely that the fact that the interrogators lied to the suspect about the test result would also be allowed to be presented. > > It’d be up to the trial judge, and would hinge in part on precedent and case law in the jurisdiction. And, of course, subject to appeal if there’s a conviction. I believe the test is whether an innocent person of normal intelligence would admit guilt under the circumstances. Just lying about the lie detector results wouldn’t cross that threshold. FWIW, the lie detector test doesn’t work if you tell the truth about the results, because the results are worthless. It only works because people don’t know that a lie detector isn’t accurate, so when you tell them they failed, they assume that they have been caught and confess.