# A lot of forensic methodologies are being debunked - Why were they ever assumed to be valid? **URL:** \ **Category:** Factual Questions\ **Created:** [September 3, 2009, 6:13pm UTC](https://boards.straightdope.com/t/a-lot-of-forensic-methodologies-are-being-debunked-why-were-they-ever-assumed-to-be-valid/508774 "2009-09-03T18:13:37Z")\ **Posts on this page:** 5\ **Page:** 2
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [September 4, 2009, 1:45pm UTC](https://boards.straightdope.com/t/a-lot-of-forensic-methodologies-are-being-debunked-why-were-they-ever-assumed-to-be-valid/508774/21 "2009-09-04T13:45:46Z")
On a related note, ‘profiling’ (say of serial killers) has long been debunked, but it’s one of the first things most of us learned about when it comes to so-called incredible techniques used by investigators. We also learned of the ‘lie detector’ and hand-writing analysis. Skeptics Dictionary covers most of these topics very well. [www.skepdic.com](http://www.skepdic.com) ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [September 4, 2009, 4:56pm UTC](https://boards.straightdope.com/t/a-lot-of-forensic-methodologies-are-being-debunked-why-were-they-ever-assumed-to-be-valid/508774/22 "2009-09-04T16:56:22Z")
> [@Sage\_Rat](#): > > Testing of polygraphs appears to work, the closer the test scenario is to a real test of guilt of a crime. They can however also be easily beaten. The only thing the Polygraph is good for is either getting dudes to confess prior to screening or showing them a line at random and saying "Look the Lie Detector here has said you lied, do you want to tell us the truth? ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [September 4, 2009, 11:04pm UTC](https://boards.straightdope.com/t/a-lot-of-forensic-methodologies-are-being-debunked-why-were-they-ever-assumed-to-be-valid/508774/23 "2009-09-04T23:04:44Z")
I’ll go along with Gazwart’s last sentence. Get a self-described “expert” who talks in a convincing way and what is the jury supposed to think. Sure the defense can try to refute it, but then it becomes a matter of whom you believe. There ought to be standards of evidence and judges who understand these issues enough to disallow such testimony. I believe there are still people in jail on the basis of “evidence” elicited by hypnosis, although abundant evidence exists that such testimony is useless since a hypnotist can get a person in a trance to say anything and there is no reason to think that people under hypnosis have any better recall that conscious people. Prosecutors will use anything that gets convictions. ---
**Author:** ![IAmNotSpartacus](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@IAmNotSpartacus](https://boards.straightdope.com/u/IAmNotSpartacus)\ **Post date:** [September 5, 2009, 5:13pm UTC](https://boards.straightdope.com/t/a-lot-of-forensic-methodologies-are-being-debunked-why-were-they-ever-assumed-to-be-valid/508774/24 "2009-09-05T17:13:25Z")
> [@DrDeth](#): > > The only thing the Polygraph is good for is either getting dudes to confess prior to screening or showing them a line at random and saying "Look the Lie Detector here has said you lied, do you want to tell us the truth? I don’t think the polygraph would be good for either of these situations. I think the threat of a polygraph leading to a confession could be construed as a confession given under duress. And certainly anything that is said during an actual polygraph will almost certainly get tossed out of court long before a jury hears it. Legal eagles correct me if I am wrong, please. ---
**Author:** ![gonzomax](https://avatars.discourse-cdn.com/v4/letter/g/e8c25b/32.png) [@gonzomax](https://boards.straightdope.com/u/gonzomax)\ **Post date:** [September 5, 2009, 6:10pm UTC](https://boards.straightdope.com/t/a-lot-of-forensic-methodologies-are-being-debunked-why-were-they-ever-assumed-to-be-valid/508774/25 "2009-09-05T18:10:20Z")
My favorite is the unshaken belief people have in fingerprint ID. The experts have to make an ID with smeared, or partial prints and pretend they have proof . The article says that experts could not agree with each other when tested, yet we think it is factual. It is another cop myth. [Previous page](https://boards.straightdope.com/t/a-lot-of-forensic-methodologies-are-being-debunked-why-were-they-ever-assumed-to-be-valid/508774.md?page=1)