Re: latent fingerprints

From: charlie strauss <cems_at_earthlink_dot_net>
Date: Fri Dec 08 2006 - 12:13:08 CST

First I think this worrying about fingerprints issue is edging towards the realm of fume huffing. If I wanted to know which ballot was yours , I could figure out ways a lot simpler than finger print analysis. e.g. just give them a bag of polonium porkrinds before they go in the polls. On the less fantastic side, I've got bags of microtag poweder sitting in my desk drawer (it's used to tracably serial number mark everthing from gunpowder to designier jeans: it looks and acts like fine soot till you put it under a microscope--then you see a colored plastic bar code). it would be easy to get this onto someones hands. Or, even more realistically, i'd just edge mark the ballots ahead of time: draw a fine diagonal line across the edges with a magic marker--then I could always recreate the ballot order later.

However taking it as a challenge to somehow scan fingerprints.... First the kind of blunt instruments in use for oval scanners wont have the resolution. But since some folks want to replace those with high resolution scanners, then one approach might be to use a UV fluorescent light in the scanner. Finger prints exhibit some weak phosphorescence. Unfortunately most white paper also contains "whiteners" that are fluorescent as well so there's going to be a signal to noise issue. You might be able to boost that some if you had a way to pulse the illumination and time-gate the optical signal. But that would be one heck of piece of scanner hardware. If you selected the whitener carefully you might be abled to have it quenched by the finger print oil itself.... Or better yet, don't order ballots that are naturally fluorescent.

perhaps a better approach would be to give the person a slighty leaky pen and assume they would get it on their fingers.

-----Original Message-----
>From: Jerry Lobdill <>
>Sent: Dec 8, 2006 9:31 AM
>Subject: Re: [OVC-discuss] latent fingerprints
>I'm not confusing anything. The assertion was made that the
>fingerprints on a ballot could be detected somehow when the scanned
>image is viewed. I want to know how that would be done.
>At 09:33 AM 12/8/2006, you wrote:
>>From: "Edmund R. Kennedy" <>
>> I'm not sure but I believe you are confusing latent
>> fingerprints with 'invisible' fingerprints. Latent prints are
>> effectively invisible unless some sort of dye particles are added
>> that stick to the residual finger oils and so forth to make them visible.
>>10777 Bendigo Cove
>>San Diego, CA 92126-2510
>OVC-discuss mailing list

OVC-discuss mailing list
= The content of this message, with the exception of any external
= quotations under fair use, are released to the Public Domain
Received on Sun Dec 31 23:17:09 2006

This archive was generated by hypermail 2.1.8 : Sun Dec 31 2006 - 23:17:16 CST