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G o o d   M o r n i n g !
Monday, July 30, 2007

The purpose of the Detail is to help keep you informed of the current state of affairs in the latent print community, to provide an avenue to circulate original fingerprint-related articles, and to announce important events as they happen in our field.
Breaking NEWz you can UzE...
compiled by Jon Stimac

Rail Vandal Caught by Fingerprints Left on a Beer Bottle  THE WHARF, UK - July 25, 2007 was fingerprints left on the bottle that provided the final piece of evidence needed to bring him to court...

No Fingerprints on Guns Used to Kill Victim HINDU, INDIA - July 25, 2007 ...a fingerprint expert told the court that the suspect's fingerprints were not found on the murder-weapon...

Would You Buy Groceries With A Fingerprint? THE CONSUMERIST, NY - July 24, 2007 ...after signing up and associating your fingerprint with your credit card, you can buy groceries...

Fingerprints Foil His Attempt to Assume Her Identity in Jail ORLANDO SENTINEL, FL - July 21, 2007 "...he fooled us...but fingerprints do not lie..."

Recent CLPEX Posting Activity
Last Week's Board topics containing new posts
Moderated by Steve Everist

Latent Print Examiner Positions - CONUS/OCONUS
wkpetroka 1559 Mon Jul 30, 2007 12:46 am

The Lockerbie Connection.
Iain McKie 11014 Sun Jul 29, 2007 11:49 pm

Statistics and Misidentifications - The weeks Detail
Michele Triplett 12658 Sun Jul 29, 2007 11:40 pm

San Diego IAI Conference
Steve Everist 69 Sun Jul 29, 2007 4:43 pm

New Fingerprint Technique Could Reveal Diet, Sex, Race???
nctindle 439 Fri Jul 27, 2007 12:20 am

Bank Robbery
Brian Moline 478 Thu Jul 26, 2007 8:07 pm

MIDEO digital photography system
Pat A. Wertheim 826 Thu Jul 26, 2007 6:21 pm

tell all job description for LPE in Colorado
sandra wiese 1184 Thu Jul 26, 2007 12:02 am

Suggeested Reading
Bill 761 Thu Jul 26, 2007 12:00 am

need help from CA AZ and NM clpex peeps, please
sandra wiese 145 Wed Jul 25, 2007 11:58 pm

Interesting Tidbit 3
Charles Parker 621 Tue Jul 24, 2007 12:28 am



No major updates to the website.


Last week

many of us attended the IAI conference in San Diego.  It was the largest IAI conference ever with over 1,600 attendees!  More to come on subjects covered throughout the week.

This week

we take a look at the concept of color blindness and latent print examination.

Color Blindness in Latent Print Examiners
by Pat Wertheim

At the fall meeting of the Scientific Working Group on Friction Ridge Analysis, Study, and Technology (SWGFAST) in 1999, a discussion of physical traits of fingerprint examiners included the topic of color blindness. Some of the members wondered whether examiners should not have a good ability to distinguish colors. My personal situation is that while I believe I can see colors correctly, I have never been able to pass all of the color tests during an eyesight examination. I have what I believe is commonly called “red-green color blindness.” It usually shows up on the color tests with the hidden numbers in patterns of different colored polka dots. I cannot find most of those hidden numbers. Whatever the technical name of the condition, I am color blind to some degree.

However, I know from looking at latent prints, photographic enlargements, and images on computer screens that I can detect subtle differences in shades of gray that other examiners cannot see. I can frequently see ridge endings very clearly that another excellent latent print examiner in our laboratory has great difficulty pinpointing, unless she first enhances the latent print image to darken the ridges and lighten the furrows. It is plain to both of us that my eyes are more sensitive than hers when it comes to being able to distinguish between close shades of gray. On the other hand, her ability to distinguish between colors is markedly better than mine, especially with tan, light brown, beige, etc.

The light sensitive receptors in the retina of the eye are called rods and cones. They “fire” when struck by light and send impulses to the brain, where an image is formed. Rods are hundreds of times more sensitive than cones, but they only “see” light in its overall intensity and in shades of black and white and gray. Simply put, cones work better in bright light and are the receptors that allow us to see color.  Rods, on the other hand, work very well in dim light but they do not see color. One effect of this is that people with more than the average concentration of rods and fewer cones are “color blind” to the degree the rods predominate.  Another effect of a predominance of rods is better night vision. Still another effect, this one of special interest to latent print examiners, is a better than average ability to distinguish between very close shades of gray.

There are other conditions related to vision that affect a latent print examiner’s ability, such as form blindness and dyslexia. An examiners ability to memorize and compare ridge detail between two images would be adversely affected by either of these conditions. The mild presence of either of these conditions might not prevent a person from becoming a good latent print examiner, but the more serious the condition, the harder the latent print examination would be for that examiner.

There are a number of technical and medical terms referring to different deficits in color sensitivity. But experience and study (sources not noted) indicate that color blindness is almost certainly not an impediment to latent print examination and can, most likely, be an asset.

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Until next Monday morning, don't work too hard or too little.

Have a GREAT week!