CLPEX Chat Board

I would like to propose a research project, which perhaps an LPE here on CLPEX can tackle and publish.

GOAL: With what frequency do latent fingerprints become (lateral reversals) in the normal unwinding and processing of overlapping adhesive tapes?

Research Idea example:

Have un-gloved persons wrap multiple "simple" items in several different kinds of tape. Perhaps using 12 inch sections of tape to increase the handling and potential for latent prints. Do not tell the subjects how to or why they are wrapping the item, simply to cover the box in several layers of tape, or use all tape provided.

-Small boxes wrapped in black electrical tape.
-Small boxes wrapped in silver duct tape.
-Small boxes wrapped in brown packing tape.

Process the tape as normal and record the number of latent fingerprints developed, the number of normal read prints, and the number of lateral-reversed fingerprints. I think most examiners would assume the adhesive side is the "correct read" side. I'm wondering how many prints are lifted by the adhesive of the tape itself, thus become lateral-reversals that are not manually matched or matched in AFIS. Perhaps such test will give a rough percentage of reality. I would expect it to be low, but I can't intuitively guess such a number.


This research would be a serious benefit to all latent examiners and AFIS users. Perhaps, it would be ideal if all AFIS computer could "automatically" search all latents as lateral reversals and notify the user if a high score is realized. Essentially, a hidden side search.

Very Sincerely,
Craig Coppock

Back in 1999, I was co-author of a paper in the "California Identification Digest" (California State Division-IAI's publication) based on a case I worked with a previous employer: Lateral Transfer Phenomena, California Identification Digest, vol. 99, no. 5, May 1999, pp. 2-3. The case involved developing latents on electrical tape (adhesive and non-adhesive sides) removed from a revolver. Among the references used were Jim Cowger and Pat Wertheim.

Darrell Klasey
Latent Fingerprint Examiner
Solano County Sheriff's Department

Journal of Forensic Identification: 38:6 (1988), 42:5 (1992), 44:5 ((1994), 50:2 (2000), 55:6 (2005)

Articles address laterally reversed (trnasferred) latents from one surface to another. 50:2 is on ninhydrin transfer and 42:5 deals with adhesive tape.

Thanks to all for the reference material information on this topic.

What I have learned thus far is:
- Lateral reversals are much more common with some surfaces than historically thought.
- Adhesive tape surfaces are known culprits for lateral reversals.
- There has not been much research in this area.

This brings up the question of the ratio between "right read" and "wrong read" laterally reversed latent prints. This is especially noteworthy, when some processes develop a disproportional number of prints on only one side of the tape. I would suspect in some cases, and with some processes the laterally reversed prints would not have a "right read" counterpart. These prints would not match in AFIS, and may be overlooked in the comparison process.

Just food for thought...or fuel for research.