Latents from latex gloves

[Sara Rafferty]

I am currently doing graduate work for a masters degree in forensic science and law at Duquesne University. I chose to focus on latent fingerprints and my research will be based upon finding the most reliable method for lifting latents from latex gloves. I have found lots of information on gelatin lifters (black) as well as the Ninhydrin-heptane carrier method. Besides the normal powder methods, I was hoping for some further input as to what has worked for other people as well as information regarding certain circumstances such as environmental exposure and time between the actual crime and discovery of the evidence. I am extremely new to this particular field and would greatly appreciate any feedback or suggestions. I hope to further the research by using different variables (tightly fitting gloves as opposed to loose) and would even appreciate some input on that subject as well. Thanks ahead of time for your help!

[Mary McCarthy]

Sara,
At the last meeting of the IAI in August of this year, a paper was presented on this topic by J.N. Zonjee from the Netherlands. "Visualization of latent fingerprint on used vinyl and latex gloves using gellifters" is the title of the paper. The author is M.J.M Velders, also from the Netherlands.
My own experiece with this type of item is that most methods are often not productive. However, I have developed excellent prints on occasion using cyanoacrylate fuming followed by dye staining with Rhodamine 6G and LASER examination.
I hope you plan to publish your findings.
Mary M.

[Patrick Warrick]

Sara,

I agree with Mary McCarthy in that the recovery of suitable latents on latex gloves is very difficult. However, using the technique described by Mary, I have on about 3 occasions used cyanoacrylate fuming with dye stains and not visualized anything because of inherent luminesence of the latex glove. I then applied magnetic powder and was able to develop suitable latents.

I recently read in the Technical Notes on Sudan Black put out by Lightning Powder that it can develop latents using a dipping technique. I personally have not researched this yet, but it is something to look into.

Patrick

[g.]

Sara,

Good luck with your research. Obviously given a choice of 2 techniques, it would seem that DNA would be the most likely to produce something (though a fingerprint may be more advantage when an unknown subject is involved b/c of the sheer volume of prints in the AFIS databases compared to CODIS.

I would think an interesting research project is to compare the recovery of DNA v. Fingerprints from various conditions as you described. I would also have groups of = just DNA processing, just FP processing and one group where FP processing follows DNA processing to see if swabbing for DNA will affect your FP recovery.

Good luck. Be sure to publish and let us know your findings. All too often grad students discuss their projects and then we never hear the results!

g.

[Neville Morris]

It is always a safe bet to use cyanoacrylate fuming to harden the print, then apply powder or a dye staining but leave the fumed glove for about 24hrs before staining, this gives the superglue fumes adhered to the latent time to harden, you could wash off the latent print if staining is applied too soon.

Next you need to check out what the inherent luminescence of the latex glove is, do this by using a tuneable light source (Polylight or equivalent).
Now you will know the wave length that gloves will start to fluoresce at. Next trick is to choose a dye that will fluoresce at a different wave length. A quick easy method I learnt at the Aussie f/p Centenary was to use a yellow highlighter it glows at about 415nm, be careful as you pass it over the latent as it may wipe it off, it's a starting point, if it works look for some basic yellow dye in your lab. The other commonly used dye in this county is safranine O, although in the US the labs use an equivalent, which will fluoresce at about 530nm.

Make sure you use safety goggles that will give you the wavelength shift you need to achieve whilst protecting your eyes.

There is lots of study done on DNA after fingerprinting so the reverse would be interesting. But the method used to gather the DNA would need to be non destructive as fingerprints are often very fragile.

These Best of luck. Look forward to seeing your results.

[Charles Parker]

Mr. Morris:

but leave the fumed glove for about 24hrs before staining, this gives the superglue fumes adhered to the latent time to harden, you could wash off the latent print if staining is applied too soon.

I was curious about the part to let it set for 24 hours to harden. The staining might wash the latent print off of the surface.

I have not read that before. Or at least not that I can recall. Is your source from an article or 1st hand experience.

The reason I ask is that I teach those two subjects (glue and dye staining) and I need to add that to the training outline.

Thanks for the posting.

[Danny L. Harness]

Charles,
A helpful resource may be: www.detectoprint.com

[Crimcon]

I agree with the glue/powder camp on this one. I worked a burglary case with gloves that I developed and identified the suspect on using superglue, then magnetic powder, then photography (of course!) I identified two fingers, and even developed a perfect palm print. Timeframe wise, the time between the offense occurring to processing was about 4 months.

In addition, be aware that there are latex gloves that contain a fine film of talc in them. These set up their own processing method by becoming a "paste" when exposed to perspiration from the hands. Once the glove is removed, the "patent," or visible, image of the ridge detail from the hand/fingers is visible, impressed into the talc paste. I know of a man who identified a suspect in such a scenario. . .

Hope this helps.

[Tony.. FSS]

I've found the best results come from CNA, Rhodamine 6G then Multiple MetAL Deposition.. Had positive results with this method.

I did try the gel lifter method as an experiment but could not get it to work.