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G o o d   M o r n i n g !
via THE WEEKLY DETAIL
 
Monday, January 26, 2004


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
 

Delayed Fingerprint Match Results in Rape Indictment - TIMES PICAYUNE, LA  - Jan. 23, 2004. ...a fingerprint match that took four years to obtain has resulted in the indictment of a man in a rape case...

Fear About Fingerprints - ATLANTA JOURNAL-CONSTITUTION, GA - Jan. 22, 2004 ...fingerprinting foreign visitors may close the door on terrorists, but officials worry it might also yank the welcome mat....

Man Freed in 1997 Shooting of Officer - BOSTON GLOBE, MA - Jan. 24, 2004 ...Judge gives ruling after fingerprint revelation...

Man Accused in Dual Slayings Caught in Ohio - ATHENS BANNER-HERALD, GA - Jan. 22, 2004 ...suspect originally gave a fake name, and his true identity was learned after his fingerprints were run through AFIS...

 

Gary Pond passes on news regarding his Porter Cases:

We are pleased to announce that we have just been added to the News Desk on the opening page of the Photographic web site as at
http://www.photographic.com/ 

We have also been told that the new Rolling Softie 160 will be shown in the new products section of the April issue of Peterson's Photographic.

Laptop Magazine just featured us in their New Products section with an Elite case and will show the Rolling Softie case the following month.  We will run a new 1/2 page ad in this publication.


Rangefinder, eDigital and others are also showing new product information or writing articles about our newer Porter Cases.

Gary E. Pond, President
PORTER CASE, INC., South Bend, IN USA
www.portercase.com
800-356-8348
574-289-2616
FAX 574-289-2747


(this is not a paid advertisement... I own one of Gary's cases, and it has been a back-saver on many occasions!)

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Last week, we looked at the future of AFIS and the fingerprint field.  This week, we look at some new research and a new product for the development of latent prints on thermal paper.  This week's Detail was obtained from http://www.bvda.com/EN/prdctinf/en_thermanin.html

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Manual of use for ThermaNin

Introduction

Queue ticket treated with regular ninhydrin solutionThermal paper, once mainly used as fax paper only, is now used in many applications. These days it is used in ticket dispensers for giving out queue numbers or parking tickets, in label printers, and printers for point-of-sales receipts at retail shops like supermarkets.

Thermal paper turns black on application of heat (as in the printer) but also on contact with polar solvents like alcohols, acetone, ether, ethyl acetate etc. The regular solutions of fingerprint reagents like ninhydrin and DFO are either based on a polar solvent (ninhydrin in ether or acetone for example) or rely on certain amounts of these polar solvents to dissolve them when used in an apolar bulk solvent like petroleum ether or heptane.

Queue ticket treated with ThermaNin solutionThese solutions have a detrimental effect on thermal paper: on application the paper surface turns dark grey or black thereby obscuring any fingerprints that may subsequently develop.

There are only a few techniques known for developing fingerprints on thermal paper:
 

  • 1,2-IND (as a 2 g/l solution in HFE-7100 containing 7% ethyl acetate) has been reported to develop fingerprints without darkening the top (active) layer of the thermal paper (John Stimac, Journal of Forensic Identification, 2003, 53(3), 265-271). For finding and photographing the developed prints a Polilight or similar light source is needed.
     
  • DMAC (dimethylaminocinnamaldehyde) fumes react with fingerprints on thermal paper (see e.g. Brennan et al., Journal of Forensic Identification, 1995, 45(4), 373-380). The fluorescence of any developed prints can be photographed with green light (Polilight, around 530 nm).
     
  • Exposure to the fumes of concentrated hydrochlorid acid was reported to develop prints on the top layer of thermal paper (Broniek, Knaap, Journal of Forensic Identification, 2002, 52(4), 427-432). It will not develop prints on the back of thermal paper.
     
  • Treatment with a regular ninhydrin solution and after allowing ample time for development of fingerprints, rinsing the paper with an excess of acetone to remove all the text and/or grey-black stains.
     

These techniques may not be appropriate, or the additional equipment needed not available.

Japanese researchers have published that hemiketals of ninhydrin, obtained by exchanging the water molecule in ninhydrin [also known as 1,2,3-indantrione monohydrate] for an alcohol, are soluble in apolar solvents like petroleum ether without the need for addition of polar solvents. The solutions were reported to develop fingerprints on thermal paper, without darkening of the surface.

Such a product (named ThermaNin) is now
available from BVDA.

To our knowledge, the effectiveness of the different techniques has not been compared.

How does ThermaNin work

ThermaNin will not develop any fingerprints by itself. The process relies on the fact that after application of its solution to paper, ThermaNin will readily convert to ninhydrin and the alcohol upon contact with water present in the paper or in the atmosphere. This conversion can be detected from the weak odor of the alcohol that will be given off by the paper afterwards. The ninhydrin will then be available to react with any fingerprint residue in the paper. The ninhydrin will not dissolve in petroleum ether, so the paper can be dipped twice (with a certain waiting time in between, to allow for the conversion of the ninhydrin hemiketal to ninhydrin and alcohol) to increase the ninhydrin concentration in the paper.

Manual of use

Detail of queue ticket treated with ThermaNin solutionDue to the sensitivity of ninhydrin hemiketals (like ThermaNin) towards water, their solutions in petroleum ether cannot be stored long without degrading the performance. A working solution should be used soon, at least within 1-3 weeks. Therefore, we cannot supply working solutions, they should be made fresh when needed. The ThermaNin crystals that we supply are fairly resistant to atmospheric humidity and have no apparent shelf life when stored in tightly sealed containers.

A working solution that takes not too long to prepare, by dissolving the ThermaNin powder in petroleum ether/pentane or heptane by shaking (for 5-10 minutes), contains 4 gram per liter (or 0.4 gram per 100 ml). Slight warming of the solution (till around 30-40 C) will aid the dissolution of the ThermaNin powder considerably.

Precipitated ninhydrin in a ThermaNin solution
German researchers at the BKA in Wiesbaden found that for dissolving, application and storage of working solutions of ninhydrin hemiketals either plastic or aluminium containers should be used, with a strong preference for aluminium. Generally speaking petroleum ether etc. diffuses out of plastic bottles and water in, aluminium does not have this problem.

In glass bottles the shelf life of the working solutions is drastically shortened. This is probably due to the small amount of water adhering to the walls and the slightly acidic nature of the glass surface (accelerates the reaction between water and ThermaNin).

Development of the fingerprints can be done in the usual manner: at room temperature, in the dark and elevated humidity (around 80% is preferred). Because of the nature of thermal paper heating of the paper to accelerate development of the prints is not possible: the paper will turn dark.

Because of the sensitivity of the paper for polar solvents, treatment of the thermal paper with zinc chloride is not an option either.

Safety

On contact with water ThermaNin will readily fall apart in ninhydrin and alcohol. Therefore, the safety characteristics of the product can be judged from those components. Ninhydrin is considered harmful if swallowed and irritating to eyes, skin and respiratory system; the alcohol as a skin and eye irritant. The precautions taken when working with ninhydrin (protective clothing, gloves, safety glasses when working with the solutions) will be sufficient for this product too.


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To discuss this Weekly Detail, log on to the CLPEX.com message board: (http://www.clpex.com/phpBB/viewforum.php?f=2)

More formal latent print discussions are available at onin.com: (http://www.onin.com)


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MANAGEMENT CIRCLE

(I reproduced this here because I could sure stand to follow this advice!...)

Learn to say 'No' with grace


A colleague has just asked you to work on a time-consuming project, and you would like to decline gracefully.  Here's how:

1) Beware the automatic "Yes."  You may hate to flatly turn somebody down, but remember it's much harder to get out of something you've already agreed to than to turn it down immediately.

2) Buy time.  Unless you're already certain of your response, ask for time to think about it.  That is both a reasoable and truthful response.

3) Be direct.  If the answer is "No," say "No."  Say it respectfully, but say it.  Example: "I'm really flattered that you'd think of me.  But I'm going to have to turn the opportunity down."  And then, be quiet.  Avoid the impulse to give a list of reasons.  That will only open the issue for discussion and give your colleague an opportunity to talk you out of your decision.

-Adapted from Time Management, Marshall, J. Cook, text from the November 2003 issue of Communication Briefings, briefings.com.

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UPDATES ON CLPEX.com


Updated the Bookstore with sold items; I will be adding a few new items this week (for real this time!) for posting next Monday.

Updated the
Newzroom

Updated the
Detail Archives

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

Have a GREAT week!