# Unique bodily identifiers? **URL:** \ **Category:** Factual Questions\ **Created:** [March 1, 2004, 11:54pm UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993 "2004-03-01T23:54:10Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Otto](https://avatars.discourse-cdn.com/v4/letter/o/bbe5ce/32.png) [@Otto](https://boards.straightdope.com/u/Otto)\ **Post date:** [March 1, 2004, 11:54pm UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/1 "2004-03-01T23:54:10Z")
Fingerprints. Dental records. DNA. Retinal patterns. Other physiological features which can be or are used as unique identifiers? I’ve heard in addition to the above: footprints; ear shape; voice print. But nothing really substantive to back them up. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 2, 2004, 12:12am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/2 "2004-03-02T00:12:08Z")
Besides retinal patterns, the patterns of the iris can also be used. ---
**Author:** ![kezami](https://avatars.discourse-cdn.com/v4/letter/k/eb8c5e/32.png) [@kezami](https://boards.straightdope.com/u/kezami)\ **Post date:** [March 2, 2004, 12:26am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/3 "2004-03-02T00:26:06Z")
Butt cheeks 🙂 ---
**Author:** ![donkeyoatey](https://avatars.discourse-cdn.com/v4/letter/d/e47c2d/32.png) [@donkeyoatey](https://boards.straightdope.com/u/donkeyoatey)\ **Post date:** [March 2, 2004, 2:35am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/4 "2004-03-02T02:35:56Z")
I think it’s a no on [ear shape](http://www.forensic-evidence.com/site/ID/ID00004_4.html) : > [@](#): > > There is, however, no empirical data to date that proves the underlying premise: that the ears of a human being are in fact so different and distinguishable that their detail is never duplicated. The only (non-scientific) argument in support of ear individuality that has been forthcoming is always a reference to the familiar saying that “nature never duplicates itself” or that “all snowflakes are different.” ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [March 2, 2004, 3:06am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/5 "2004-03-02T03:06:39Z")
Lines on ones lips are pretty good. Fairly simple for computer generated id systems. But the issue is, um, data acquisition. You know, sanitation, creepiness, etc. But once cheap long range digital cameras become commonplace, they’ll be able to do scan you from 20 feet away. Then everyone will start wearing thick lip gloss when going to WalMart. Note that bite marks are sometimes used in criminal trials, but I wouldn’t convict someone if that was all the evidence. Footprints are as good as fingerprints, but you have to have good copies made ahead of time. Usually not available for iding a body found in a ditch. Voice prints are more magic than science. Many European intelligence agencies have proclaimed the Bin Laden tapes to be fakes while the CIA says they’re real. Pretty much in the same class as “lie detectors.” ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [March 2, 2004, 3:27am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/6 "2004-03-02T03:27:26Z")
What about a map of the lines on your palm? ---
**Author:** ![gooti](https://avatars.discourse-cdn.com/v4/letter/g/eb8c5e/32.png) [@gooti](https://boards.straightdope.com/u/gooti)\ **Post date:** [March 2, 2004, 5:39am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/7 "2004-03-02T05:39:30Z")
About a year ago I remember watching a show on one of those educational channels (TLC, HIST, COURT TV, DISC, etc.) that covered, IIRC, a bank robbery where a man dressed as a woman, lipstick and all, was trying to escape the bank and ran face-first into the glass door leaving behind lip prints. Subsequently, he was identified by the lip prints left behind and convicted of armed robbery. I tried to find it online but had no luck. But, then again, I’m quite lazy. ---
**Author:** ![Lissa](https://avatars.discourse-cdn.com/v4/letter/l/85f322/32.png) [@Lissa](https://boards.straightdope.com/u/Lissa)\ **Post date:** [March 2, 2004, 7:37am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/8 "2004-03-02T07:37:12Z")
How about scent? Except in those with poor hygeine, it wouldn’t be readily apparent, nor do I think any technology has been developed to detect it, but supposedly a dog can. Years ago, I remember seeing a documentary on tracking dogs which stated that each individual person’s scent is unique, and cannot be masked, even with perfumes. So, maybe “body odor” counts as a physiological identifier. ---
**Author:** ![Ranchoth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranchoth/32/1066_2.png) [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)\ **Post date:** [March 2, 2004, 7:57am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/9 "2004-03-02T07:57:09Z")
X-Rays. Or bones, period. By superimposing a photo of a skull over a photo of a person (at the same angle, etc.) you can determine if the skull belongs to the person in the photo or not. ---
**Author:** ![Astra](https://avatars.discourse-cdn.com/v4/letter/a/f14d63/32.png) [@Astra](https://boards.straightdope.com/u/Astra)\ **Post date:** [March 2, 2004, 8:21am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/10 "2004-03-02T08:21:07Z")
Lip and ear prints are unique. I believe a recent case did admit a comparison of an ear print to that of the suspects. Palm and footprints, like fingerprints, are also unique, but are usually not kept on record. These types of evidence can only be used when there is a known suspect to compare the prints to, while there are several fingerprint databases that can be checked for an unknown print. ---
**Author:** ![Astra](https://avatars.discourse-cdn.com/v4/letter/a/f14d63/32.png) [@Astra](https://boards.straightdope.com/u/Astra)\ **Post date:** [March 2, 2004, 8:29am UTC](https://boards.straightdope.com/t/unique-bodily-identifiers/231993/11 "2004-03-02T08:29:19Z")
In [this case](http://www.forensic-evidence.com/site/ID/dallangher_UK.html) a man was found guilty via an ear print that turned out not to be his. The danger of “cutting edge” evidence. [Another admission of ear print evidence](http://www.forensic-evidence.com/site/ID/ID_Kunze.html) [Lip prints](http://www.forensic-evidence.com/site/ID/ID00004_10.html) haven’t been subjected to serious study yet, from the looks of things. The [Charlottesville Police](http://www.charlottesville.org/default.asp?pageid=BCE7A828-1E1D-44D0-B09F-FDED2D9395D0) claim to have used the method at least once. It sounds viable, just not fully documented yet.