Lab report 1 - summary of lab 3 PDF

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Athena Childers CRM- 343 Professor Braziel 23 September 2018 Lab Report 1 On September 11th 2018, we as a class went to the Crime Scene House. The point of this lab exercise was to use presumptive tests, alternate light sources (ALS) and luminol, and amido black to look at fingerprints in blood. The first station I was at was all the presumptive tests for blood. The first presumptive test we did was the Phenolphthalein Test, presumptive blood test. For this test, we did two trials on the “red liquid” spatters on the tile. Both of test seemed positive, at the time of the two tests, they had a slight pink hue to them. We ended up doing a third trial from the “red liquid” spatters on the bone. Immediately, that test was very pink. Eventually the first two q-tips turned pink. The second test that was conducted was the Leucocrystal Violet presumptive test. This test was also conducted on a different “red liquid” spatter on the bone. That test immediately turned blue as it was supposed to. The third test conducted was the Heme Stix. It was a confusing one to figure out. A sample from the linoleum was used for this test. The outcome for this test is supposed to turn red if heme was present, however, it did not change color at all. This would mean that presumably it was negative and not blood. The last test conducted was the Tetramethyl Benzidine PBT presumptive test. We took the sample from the pink shirt. The q-tip first was green, however, it eventually had a blue hue to it. The second station was ALS and luminol. We first saw a dark brownish-red stain on the floor. We put on our orange eyewear, turned off the lights and sprayed the stain. The stain become luminescent. Next for the ALS, we saw two white stains on a blanket on the bed. We put

our orange eyewear back on, turned on the UV light and turned off the lights. Only one stain lit up, which can only mean that the one stain was possibly semen. For the third and final station, which was Amido Black, we took a tile which had a “redliquid” stain on it with a fingerprint. We used the amido black to see the fingerprint more clearly. After doing all the steps and eventually rinsing the print with water, the amido black stuck to the print and the fingerprint was very clear and crisp looking. This was a great exercise that was conducted at the crime scene house. Doing a test like this before a test makes the information sink into your head more....