You better do well with this You better do well with this PowerPoint! PowerPoint!

Paper Chromatography Fingerprints DNA evidence Shoeprints & tire treads Soil Spatters Polymer Testing/ Natural and Man-made

substances (I’ll try my best with this one since I barely know much about it myself.)

What we’re covering…

1. Take a coffee filter and draw a dot on it with the substance given

Paper Chromatography Procedure

2. Place the coffee filter over the cup of water. Make sure that the water doesn’t directly touch the substance dot on the filter.

Instruction: Students will analyze evidence from paper chromatography (ink pens, juices, Kool-Aid, etc.). The paper chromatogram(s) will be collected with

the score sheet. No calculations are expected to be performed.

After the procedure the water should have started

to seep up towards the ink, causing colors to run.

Paper Chromatography Results

It should look vaguely like this when you’re

done.

Just as a suggestion, try to do this experiment first during the experiment that way the water can seep

through for a little longer. Not only that , but it’s simple and quick and easy to get out of the way.

This Website contains the entire experiment:

http://www.yesmag.bc.ca/projects/paper_chroma.html

Watch this youtube video to help understand how to conduct the experiment:

http://www.cleanvideosearch.com/media/action/yt/watch?videoId=-fs5btFKdXA

Websites for Chromatography

There are 3 types of

fingerprints:1.Arch

2.Whorl3.Loop

Fingerprints

Instructions: Students may be asked to identify different patterns on fingerprint evidence such as the difference between arches, whorls,

and loops.

You should know that no 2

fingerprints are alike.

You can see one way to tell the difference between the three types is where their deltas and cores are located.Delta: Triangular area usually shaped like a T-junctionCore: Center of the pattern.

Differentiating Fingerprints

Loops have one or more ridges entering from one side, curving, and then going out the same side it entered. The ridges in loops double back on themselves. All loops have elements called a delta and a core. About 65% of fingerprints have loops.

Loops

Whorls have a circular pattern and have at least two deltas and a core (center of the circles). Whorls look a little like target shapes or whirlpools – circles within circles. Whorls make up 35% of patterns seen in human fingerprints

Whorls

Arches are the least common pattern making up

only 5% of all pattern types. Arches are ridgelines that rise in the center and create a wave like

pattern. The ridges enter from one side and exit the other side with a rise in the middle. They do

not have a delta or a core and can be broken into two sub-groups:

Plain arch – which has a gentle rise.Tented arches - have a steeper rise than plain arches.

Arches

Arches (Cont.)

Websites for Fingerprints

Check out this website for a more in-depth explanation:http://soinc.org/sites/default/files/uploaded_files/

crimebusters/Fingerprinting.pdfThis has more specifics on the types of fingerprints:

http://www.odec.ca/projects/2004/fren4j0/public_html/fingerprint_patterns.htm

TAKE A BREAK WITH THE DINORAWR!!!

TAKE A BREAK WITH THE DINORAWR!!!

Match the DNA found at the crime scene with

one of the suspects The bands are lengths of DNA strands located o that

person's chromosomes The dark bands represent the end/beginning of a new DNA

strand The more bands that match a certain sample the greater

probability that their DNA are the same.

DNA Evidence

Instructions: Students may be asked to compare DNA chromatograms/ electropherograms from materials found at the scene to those suspects.

Similar to this, but in black in white.

What the Picture will look like

Shoeprints/ Tracks

Just match the print found at the crime scene with the one of the suspect’s and explain how you got that conclustion.

http://soinc.org/sites/default/files/uploaded_files/crimebusters/Tracks.pdf

I will add this part soon!

Polymers/ Fibers