> -----Original Message----- > From: Thomas Chiverton [mailto:[EMAIL PROTECTED] > Sent: Saturday, May 07, 2005 10:25 AM > To: CF-Talk > Subject: Re: HASH() reverse > > On Saturday 07 May 2005 14:23, James Holmes wrote: > > possible fingerprints. He showed that there are at least 64 billion > > fingerprints possible. Given that this is larger than the number of > people > > Firstly, of that space, not all possible combinations will occur. > Secondly, there have been some very intresting tests against police > fingerprint databases, though I can't find an URL at the moment.
I will say, before breaking the rule, that we should probably take this to community. Reply to me there if you're on it, otherwise let's take it private. ;^) The only things I've seen is that the current tests for "uniqueness" may need to be enhanced, not that fingerprints themselves are not unique. In other words the tests may be wrong and say that two fingerprints are from the same person (unlikely but possible) - but that doesn't mean the fingerprints are actually the same, just that the test lacks resolution. I believe currently "7 points of similarity" are required by most agencies - there has been talk for years of increasing that number. There are also genetic similarities in finger prints from those of the same family, but these don't seem to extend to the detail level, just general pad size and "grain" direction and so forth. But the actually process by which fingerprints is created is mechanical, not genetic - even identical twins don't have the same fingerprints. Of course the bottom line is that as we collect more and more samples we may indeed find essentially the same fingerprints on two different people (at least the same as far as our ability to test goes). This is unlikely to radically affect law enforcement since the likelihood of two people having the same prints are very small (if, indeed there is a chance) and the likelihood of two people associated with a single case having them exponentially smaller. Similar problems exist with DNA testing in that there is a very small chance that two completely different people can be found for which the test returns positive results. However again, this doesn't mean that the DNA is the same, just that the test doesn't have the resolution to expose the differences. It's rare however that ONLY DNA or Fingerprints can link somebody to a crime. They would have to had been in the area, for example, perhaps had to have known the victim and so forth. Jim Davis ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Logware (www.logware.us): a new and convenient web-based time tracking application. Start tracking and documenting hours spent on a project or with a client with Logware today. Try it for free with a 15 day trial account. http://www.houseoffusion.com/banners/view.cfm?bannerid=67 Message: http://www.houseoffusion.com/lists.cfm/link=i:4:205962 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
