# Is it possible for 2 people in the history of the world to have shared fingerprints? **URL:** \ **Category:** Factual Questions\ **Created:** [February 7, 2004, 12:26am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923 "2004-02-07T00:26:41Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [February 7, 2004, 12:26am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/1 "2004-02-07T00:26:41Z")
I was watching a bit on TV about fingerprinting last night, and it mentioned that fingerprints have “billions” of possible designs, and that got me thinking. If fingerprint possibilities are only in the billions, does that mean that two people in mankind’s history could have had identical fingerprints? After all, many more than “billions” of people have lived in the entirety of human history. Or did the program underestimate the number of possible fingerprints? Even if they did, is it still possible that every single human that has ever lived had unique prints? ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [February 7, 2004, 2:28am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/2 "2004-02-07T02:28:46Z")
With “billions” of possible ‘designs,’ whatever that means’ it is comparable to the likelyhood of a big bunch of chimps, or monkeys, or whatever banging away on typwritere trying to duplicate the works of Shakespeare. It just aint gonna happn. ---
**Author:** ![Bob55](https://avatars.discourse-cdn.com/v4/letter/b/e9c0ed/32.png) [@Bob55](https://boards.straightdope.com/u/Bob55)\ **Post date:** [February 7, 2004, 6:25am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/3 "2004-02-07T06:25:25Z")
I’m sure that some people have very similar patterns, but I don’t think it would be possible to have the same exact fingerprints down to the atom. Now maybe the same (or very similar) fingerprints seen on ink and paper, but a close-up under a microscope would surely reveal differences. ---
**Author:** ![jimpatro](https://avatars.discourse-cdn.com/v4/letter/j/b9e5f3/32.png) [@jimpatro](https://boards.straightdope.com/u/jimpatro)\ **Post date:** [February 8, 2004, 2:15am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/4 "2004-02-08T02:15:25Z")
There is no hard rule that some god invented that says no two people will ever have the same fingerprint. Its a question of probability. Low probability does not mean impossibility. I know Cecil debunked the “no two snowflakes alike” belief some time back. ---
**Author:** ![blasphmer](https://avatars.discourse-cdn.com/v4/letter/b/6de8d8/32.png) [@blasphmer](https://boards.straightdope.com/u/blasphmer)\ **Post date:** [February 8, 2004, 3:42am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/5 "2004-02-08T03:42:45Z")
> [@spingears](#): > > With “billions” of possible ‘designs,’ whatever that means’ it is comparable to the likelyhood of a big bunch of chimps, or monkeys, or whatever banging away on typwritere trying to duplicate the works of Shakespeare. > It just aint gonna happn. Errr…Last time I checked those big bunch of chimps did duplicate Shakespear, the Bible, John Grisham, and five songs from Outkast. P\>0 != P=0 ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 8, 2004, 4:59am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/6 "2004-02-08T04:59:45Z")
I’m having an early senior moment. There’s a well-known 50s sf mystery story in which a crook is caught and proved to be at the scene of a crime by a fingerprint match. But he is also proved to have a perfect alibi. The solution is that there are 64 billion possible fingerprint configurations and the galaxy now held 65 billion people. So duplicate fingerprints had to exist and a single print was no longer legal proof of guilt. But I can’t remember the name or the title or the magazine in which it appeared. My first thoughts were that it was by Isaac Asimov or Anthony Boucher, but a quick look through their stories finds nothing. I’ll find it soon enough, but maybe someone else here can supply the title. ---
**Author:** ![Horatio\_Hellpop](https://avatars.discourse-cdn.com/v4/letter/h/e5b9ba/32.png) [@Horatio\_Hellpop](https://boards.straightdope.com/u/Horatio_Hellpop)\ **Post date:** [February 8, 2004, 7:47am UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/7 "2004-02-08T07:47:50Z")
There was an actual case in the 90s (No cite, sorry) involving a policewoman’s fingerprint found in a bedroom crime scene. Even though she wasn’t a suspect, she nearly lost her job for insisting she’d never been in that house. Fingerprinting is a far shakier science that law enforcement would like us to believe. And as cloning becomes a reality, I think we’ll be seeing more cases of duplicate fingerprints. ---
**Author:** ![nocturnal\_tick](https://avatars.discourse-cdn.com/v4/letter/n/3d9bf3/32.png) [@nocturnal\_tick](https://boards.straightdope.com/u/nocturnal_tick)\ **Post date:** [February 8, 2004, 12:10pm UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/8 "2004-02-08T12:10:49Z")
> [@](#): > > _originally posted by **Krokodil** _ > And as cloning becomes a reality, I think we’ll be seeing more cases of duplicate fingerprints. Identical genetics do not create identical fingerprints, just look at identical twins. The creation of fingerprints is a random event. > [@](#): > > _originally posted by **jimpatro** _ > I know Cecil debunked the “no two snowflakes alike” belief some time back. The two snowflakes that were found to be alike were fragments of snowflake (or at least one was, as i recall). They may have had the same pattern but each could be distinguished from each other as a whole. Also whereas snowflakes follow geometrical patterns, fingerprints do not and as such have much greater variations. I recently took part in a university demonstration with fingerprints and rather than matching my print by its shape the first comparison was with the scars that crossed the print. So even if there were two identical prints, differences in size etc. as well as distinguishing non-print marks are still unique to each individual. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [February 8, 2004, 12:35pm UTC](https://boards.straightdope.com/t/is-it-possible-for-2-people-in-the-history-of-the-world-to-have-shared-fingerprints/227923/9 "2004-02-08T12:35:08Z")
Only days ago [New Scientist](http://www.newscientist.com/news/print.jsp?id=ns99994611) expressed doubts about fingerprinting. Interesting reading. > [@](#): > > Since 1998 there have been legal challenges to at least 40 convictions in the US and UK on the basis of fingerprint evidence, including one last week in the Massachusetts Superior Court. Yet despite this, and the concerns of some experts, the US Department of Justice has so far refused to sanction studies to investigate the reliability of this and other “existing” forensic techniques.