Naked Science Forum

General Science => General Science => Topic started by: paul.fr on 02/03/2008 19:58:25

Title: How do Fingerprints from Wet Fingers Differ from "Dry-finger" Fingerprints?
Post by: paul.fr on 02/03/2008 19:58:25
Say the police have my fingerprints on file, and i am stupid enough to go and commit another crime. if i had just got out of the bath then committed the crime, would they be able to match my 'dry' prints to the now extra wrinkly, slightly bloated 'wet' print?
Title: Re: How do Fingerprints from Wet Fingers Differ from "Dry-finger" Fingerprints?
Post by: Soul Surfer on 03/03/2008 09:11:07
Yes.  fingerprint identification depends on the geometrical pattern detail in the whorls and ridges on your fingerprint and not the precise size and shape of the fingerprint.
Title: Re: How do Fingerprints from Wet Fingers Differ from "Dry-finger" Fingerprints?
Post by: lyner on 03/03/2008 09:14:54
You could say that the system uses 'topology' rather than 'topography'.
Anyway, it's not necessarily all it's cracked up to be. The mere existence of a fingerprint (or partial one) is not proof positive that 'you done it'. There have been several examples of successful appeals on these gropunds, apparently.
Title: Re: How do Fingerprints from Wet Fingers Differ from "Dry-finger" Fingerprints?
Post by: JnA on 04/03/2008 00:17:17
Quote from: sophiecentaur on 03/03/2008 09:14:54
You could say that the system uses 'topology' rather than 'topography'.
Anyway, it's not necessarily all it's cracked up to be. The mere existence of a fingerprint (or partial one) is not proof positive that 'you done it'. There have been several examples of successful appeals on these gropunds, apparently.

fingerprint identification places the suspect at the scene, it's an important tool. DNA does the same, but the element of doubt is that some DNA evidence can be transferred.. a fingerprint means the persons fingers (we assume still attached to rest of the body) were there.
Title: Re: How do Fingerprints from Wet Fingers Differ from "Dry-finger" Fingerprints?
Post by: lyner on 04/03/2008 09:52:02
'a fingerprint' is far less common than a partial or damaged fingerprint; that's where  the doubt lies. Too much reliance has been placed on such evidence in the past and there have been successful appeals.