Investigating CSI – Background material Table of Contents I ...

colorless liquid. When this solution is oxidized (exposed to oxygen),
it will turn pink.
c. Hydrogen Peroxide: This is the 3% form typically found in
drugstores. Hydrogen peroxide is essentially water with an extra
oxygen atom attached to it. You can think of it as a chemical
oxidant which is contained in your kit.
4.) Deionized (D.I.) Water: While not an actual reagent, D.I. water is
sometimes included with a test kit in order to facilitate the transfer of stain
material onto your swab, filter paper, etc.
IV. APPLICATION OF THE KM TEST
Let’s assume that you’ve completed your visual examination of the scene and /
or evidentiary items, and 1) found some stains of interest or 2), had reason to
suspect that blood might be present. How is this test applied?
Before beginning, keep in mind the importance of avoiding contamination! You
should have the necessary personal protective equipment in place (gloves, etc.),
and be cautious about how you use the materials in the kit. Do not touch the
dropper-bottle tips with the swabs, try not to switch the caps of one reagent with
another, always use a fresh swab for each test, etc. Do not apply reagents
directly over the evidence please!
You’ll begin by performing a test with the positive control. A drop or two of deionized
(D.I.) water is applied to the swab to moisten it, and then the swab is
rubbed lightly against the control. Once this is done, begin applying the reagents
in the following manner:
1.) Alcohol: Apply a drop or two onto your swab.
2.) KM: Apply a drop or two onto the swab.
At this point you will need to pause for a few seconds and look for any
sign that the swab is beginning to develop a pink color. This is not
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