Corporal Russell & Mr. Garside March 20th, 2024
Finger Printing
Corporal Russell walked us through taking fingerprints and correctly lifting them. A fingerprint is made from the oils of your skin. To show a fingerprint, they use a special magnetic powder. This powder sticks to a magnet rod and is slowly and carefully drug across the fingerprints. This leaves a black outline that you can see below. Then, they place a piece of tape over the fingerprints to prevent smudging them. It is very uncommon to find a perfect fingerprint on a crime scene, so most of the time they are working with partial prints.
Documenting Evidence and DNA Swabbing
Mr. Bentley walked us through the process of DNA swabbing and documenting evidence. He gave us a paper envelope because the DNA would begin to decompose if it was in a plastic one. We properly labeled the envelopes and then used cotton swabs to test DNA. We were allowed to make up our own case numbers and crime. Mr. Bentley walked us through, step by step, how to properly document the evidence.
STEPS:
Label evidence envelope
Put on gloves
Open swabs by the bottom (completely ripping off the edge)
Swab the inside of the suspect's mouth, going around the bottom of their gums
Place the swabs back inside the packaging
Tape the top and bottom of the envelope
Label the envelope with your initials
Blue Star Testing
Mr. Garside walked us through the process of Blue Star testing. Blue Star testing is a chemical reaction that makes acidic properties light up in the dark. Things like Coca-Cola and blood will react. This allowed the Detectives to see what happened, even if the killer tried to mop up the blood. Blue Star can be bought by anyone and was developed by deer hunters. This cannot be used in rape cases.
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