T  H  E      D  E  T  A  I  L

The Detail Archives

Discuss This Issue

Subscribe to The Detail


Monday, June 16, 2003

BREAKING NEWz you can UzE...
compiled by Jon Stimac

Fingerprints Put Man on Trial 25 Years After Crime - KVIA-TV, TX - June 12, 2003 ...police found a finger and a palm print on some glass that was not in an area accessed by the public...

NJ Jury Sees Prints in Appliance - NORTH JERSEY.COM, NJ - June 12, 2003 ...the state argues that the defendant forced his girlfriend's 4-year-old son into a refrigerator as part of abuse that led to the boy's death...

Fingerprinting to Solve Car Thefts - PITTSBURGH POST-GAZETTE, PA - June 12, 2003 ...until recently, lifting fingerprints in such cases has been more of a luxury for victims than a necessity for police officers...

Martha Stewart Gets Fingerprinted - NEWSDAY.COM - June 10, 2003 ...the queen of good taste gets both hands dirty...

Good morning via the "Detail," a weekly e-mail newsletter that greets latent print examiners around the globe every Monday morning. 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.


The CFSO (Consortium of Forensic Science Organizations) attempts to influence policies and funding in Washington, DC, and they are in need of some information that perhaps you could assist with.  They are in need of examples of some situations where a forensic discipline such as fingerprints, questioned documents, etc.  was able to exonerate an innocent person.  If anyone has examples of this, Joe Polski would like you to e-mail him at iaisecty@aol.com.


Last week, Chris Grice shared his thoughts on "reverse color" latent print impressions.  This week, Lee Stonebreaker shares an idea for processing thermal paper for latent prints.


Just the same way you wanted to get the word out regarding "Rain-X" for the fuming tanks, I have another idea that a co-worker and I tripped over recently that you may want to pass on.

A newly-assigned member to our unit (Tpr. Stephen Happ) was present as I was discussing a case involving a cash register receipt printed on thermal paper. I explained why ninhydrin was not an option, and wanted to experiment with the muriatic acid process outlined in the Journal of Forensic Identification, Vol. 52, No. 4, July/August 2002, published by the IAI.  I obtained a roll of thermal fax paper to "play with", and decided to first demonstrate for Steve the problem with accelerating ninhydrin using heat from an iron.

As expected, the paper turned nearly black where the heat was concentrated below the iron. But Steve noticed at the very fringes of the darkened area, that some faint ridge detail was visible. It occurred to me that much lower heat may actually develop latent prints to that point without the application of any chemical process.

Using a 1200 watt hair dryer set on the lowest setting and held approximately four inches from the paper, I was able to easily develop several latent prints. To be certain that the developed latent prints were in fact black ridges against a white background, a known inked print was placed immediately adjacent to the best of my own developed test latent impressions for comparison. The results are not enhanced in any way; it is simply a scanned image of our results from  the thermal paper.  In the image, the dark "rectangular" print (circled in red by the webmaster) is the inked impression; all other visible prints are developed latents.

(all prints other than the red outlined print are latents)

Brief experimentation revealed that the constant application of low heat for "too long" will result in the same obliteration of the print as the iron produces. It is also a sudden occurrence. The best result was achieved by applying the heat only until the latents started to become visible (a very light gray). The heat can then be re-applied in "short bursts" to improve the contrast.  I found it helpful not to get "greedy".........one short burst too many seemed to quickly develop the background thereby deteriorating the contrast of the latent print.

Obviously, a lot more experimentation is necessary in many regards.   I imagine there are many different brands of thermal paper, each having their own composition of materials used to manufacture them.  There are also many different instruments which could potentially provide controlled heat (and possibly humidity).  (webmaster: It might also be that certain scheme's of heat and humidity application could prolong the critical point at the end of development; ie, holding the heat source further away as the print begins to develop, etc.)  I would expect that the results of this or a similar technique could vary dramatically when some of these and other elements are taken into account.  I would certainly encourage any Detail subscribers with some time and interest, to research and perfect the process, and re-submit for the rest of us to try.  Thanks to those folks, in advance!  I hope to hear more soon!!

Inv. Lee A. Stonebraker
New York State Police - Troop "E" FIU
Canandaigua, NY 


Discuss this and other fingerprint-related issues
on the CLPEX
message board off the homepage of the website, or at (http://www.clpex.com/phpBB/viewforum.php?f=2)

And as usual, the onin.com forum (http://onin.com/fp/wwwbd/) is also available for more formal latent print-related discussions.

For discussions with an international flair, check out Dave Charlton's forum at: http://charlton97.proboards12.com/index.cgi



Mark Mills came across the following political cartoon in his local newspaper.  he found the website of the artist and copied the link to the page.  Thanks Mark for this week's Funny Fingerprint Find!:


Under archives it's listed under 2003 cartoons, "stavro 060603s - 
American print.


UPDATES on CLPEX.com this week...

Updated the Newzroom

Updated the Detail Archives

Feel free to pass The Detail along to other examiners.  This is a free newsletter FOR latent print examiners, BY latent print examiners. There are no copyrights on The Detail, and the website is open for all to visit.

If you have not yet signed up to receive the Weekly Detail in YOUR e-mail inbox, go ahead and join the list now so you don't miss out!  (To join this free e-mail newsletter, send a blank e-mail to: theweeklydetail-subscribe@topica.email-publisher.com )  Members may unsubscribe at any time.  If you have difficulties with the sign-up process or have been inadvertently removed from the list, e-mail me personally at kaseywertheim@aol.com and I will try to work things out.

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

Have a GREAT week!