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a short video demonstration.
Most people you talk to will tell you that if
an item is wet you can not process it for latent fingerprints
or if it was wet when it was grabbed you won't get any prints
off it. Let's say you found a cold beer can at a crime scene
with condensation all over it because it came out of the refrigerator
into the warmer air. You have to let it dry out first to process
it, right? Wrong! You can take the item or vehicle and
process it while it is wet by using small particle reagent (wet print).
The next thing they will tell you is once you develop a latent
print with small particle reagent (wet print) you will have to let it dry
before you can lift it from the surface. Wrong again!
You can lift the latent fingerprint while it is still wet. If
you look at the small particle reagent (wet print) print after you have
developed and rinsed it with water, you will notice that in
the area of the latent print the water has beaded away from
the latent fingerprint. Place the lifting tape down directly
onto the latent print pushing in the center then working outwards
to remove the excess water. Lift the print and place on a contrasting
backing card.
small particle reagent (wet print) is like liquid fingerprint powder. When
sprayed on the surface of non-porous wet evidence, the micro
fine particles attach themselves to the latent print residues
as the solution runs off the surface. The residue is sprayed
with water to remove excess solution and the developed latent
fingerprints can be lifted with lifting tape.
Potential Uses:
Processing non-porous items covered with water or snow.
Developing latent prints on non-porous items that have been
lightly washed.
Processing items in situations where mud, dirt, or heavy dust
has covered prints making them impossible to develop by conventional
means.
For optimum results:
Always use fine, soft mist when spraying.
small particle reagent (wet print) dries silver on dark objects and dark
on light-colored objects and is available in white also.
To use small particle reagent (wet print) on wet objects:
1) Be sure spray nozzle is in "off" position before
shaking and after using to prevent leaking.
2) Shake small particle reagent (wet print) container to disperse solids.
This needs to be done frequently during the spraying process
because the particle reagent is heavier than the water and will
settle to the bottom of the spray container.
3) Adjust spray nozzle for fine, soft spray and test the spray
before applying.
4) Spray small particle reagent (wet print) onto the wet surface allowing
the agent to roll down and spread over the suspected fingerprint
area. It is best to start at the top and work to the bottom
of the item.
5) Spray area with clear water to wash off the excess small particle reagent (wet print) to view the developed prints.
6) If needed, repeat steps 4 and 5 until print is completely
developed.
7) If details in the print appear to be clogged with residual
small particle reagent (wet print), spray a fine mist of clear water over
the developed latent fingerprint.
8) Once prints are fully developed, photograph and either let
dry or lift wet by placing the lifting tape onto the print and
working from the center out. Press the tape down to remove the
excess water. Place tape on backing card and again press the
tape down to remove any excess water.
9) Dried print may then be re-photographed and lifted by conventional
means.
To use small particle reagent (wet print) on dry objects:
1) Be sure spray nozzle is in "off" position before
shaking and after using to prevent leaking.
2) Shake small particle reagent (wet print) container to disperse solids.
This needs to be done frequently during the spraying process
because the particle reagent is heavier than the water and will
settle to the bottom of the spray container.
3) Adjust spray nozzle for fine, soft spray and test the spray
before applying. If item is particularly dirty, spray with a
fine mist of water until all dirt washes away. Do not wipe suspected
fingerprint area.
4) Proceed with processing following steps 4 through 9 that
are listed above for wet objects.
small particle reagent (wet print) can be purchased in both pre-mixed solution
and powder that you mix.
The small particle reagent (wet print) can be purchased
through the Lynn
Peavey Company.
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