Today I had my Pattern and Physical
Evidence Concepts lab and we learned about all of the fingerprinting techniques
that can be used for forensic application. As I was looking for an article for
this week, I came across a method that I just did in lab so I thought I would
blog about it! A relatively new technique being used for fingerprint processing
at crime scenes involves the use of fluorescent powders, the prints resulting
from this technique can be visualized using UV light.
There
are 3 different types of fingerprints, latent (invisible), patent (visible),
and plastic. The method of documenting each type of print is different, due to
differences in the physical characteristics of each. For example, unlike patent
prints, latent prints cannot be seen by the unaided eye so assistance by a
powder or chemical is needed to view fingerprint and friction ridge impressions.
The use of fluorescence greatly enhances the visualization and recovery of
latent prints. The process is fairly simple, once a fingerprint is obtained (on
tape, glass, ect), Cyanoacrylate Ester Fuming (known as superglue fuming) is
used to harden print to perform more rigorous testing; a polymerase reaction is
responsible for this. Next, a fluorescent powder is applied with a special
brush to enhance the print when viewed under the UV light. I found this
technique to be very simple and effective in recovering all prints, even as a
first time user! Has anyone had experience in a crime lab or with fingerprinting
techniques? What do you think about this method?
Take a look at the article here
This is really cool. Mainly because it looks awesome, but for the field of forensics, we can never have too many fingerprint development methods. My favorite part of science is getting to see things work, visualizing prints that "aren't there".
ReplyDeletePattern! my favorite class ! Its crazy how scientist came up with multiple methods to visualize invisible prints. The best part for me is the color of the print which gives a great contrast with the black background.
ReplyDeleteSo instead of a two step process, this is an all-in-one fluorescent cyanoacrylate and it doesn't destroy potential touch DNA. The article says that chemists have been trying for 30 years to come up with an effective means of accomplishing this. lt will be interesting to see if this is just a novelty or if it will become the preferred method of fingerprint enhancement.
ReplyDeleteI've had experience with this (thanks patterns lab!) and it was pretty interesting! I don't know if the laboratory gives "real life" experience, our prints were fairly well developed because it was a simple print placed on a plastic container, no smudging or fast transfer, so I'd be interested to see how well this technique works in the real world!
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