Be a Detective : Finger Print and Foot Print Capture and Analysis


Hi this is a simple Instructable on how to capture fingerprints and footprints using items easily available in the market. :)

Forensic Science is the applications of a broad spectrum of sciences to answer questions of interest to a legal system. This may be in relation to a crime or a civil action. The word forensic comes from the Latin forÄnsis, meaning "of or before the forum."

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Dedicated To Daniel Haidermota, HaAn Nguyen Thi, Sahr Jalil and Waliyah Sahqani. 

Made by Manish Kumar

Teacher Notes

Teachers! Did you use this instructable in your classroom?

Step 1: Foot Print Analysis : Find a Foot Print

Find a footprint around your house in any sort of mud or sand. If you can't find one, you can make one. Just engrave your foot print in sand or gravel around your house. 

Step 2: Foot Print Analysis : Materials Needed

You will need the following materials for this experiment.
  1. Disposable Plastic Cups
  2. Plaster of Paris
  3. A Water Supply
  4. A Ziploc Bag
  5. A Shoebrush

Step 3: Foot Print Analysis : Step 1

Measure 1.5-2 cups of water in a disposable plastic cup and add it to the Ziploc bag. Next add 3 disposable cups full of plaster of Paris to the Ziploc bag. Pour water first and then plaster of Paris as the mixture heats up if you do it the other way around. Exothermic Reaction :)

Step 4: Foot Print Analysis : Step 2

Gently Stir the mixture until it has a thick soapy texture. Make sure that there are no air bubbles. If necessary add more water or plaster of Paris. (Make sure that the mixture you make is enough liquefied that you can easily pour it on the foot print.)

Step 5: Foot Print Analysis : Step 3

Pour the Mixture over the foot print. Wait for around 30 - 40 minutes. (Keep checking the thickness of the mixture over time until you have enough thickness on the top layer of the plaster.)

Step 6: Foot Print Analysis : Step 4

Once the plaster has settled, take out the part of the sand on which the footprint is present. In order to this safely, first remove the nearby sand till enough depth is created. Next, using your hands pick up the whole lump of sand including the footprint. Place the lump of sand on a smooth surface, with plaster face upside down. Remove the sand with the help of a brush to obtain the foot print. Splash some water onto the shoe cast to clean off the sand.

Step 7: Foot Print Analysis : Other Important Things

There are several important things to note while taking a footprint. For example the size of the print to figure out whether it is a man or woman. You can use the Brannock Shoe Size conversion table to do so (Given Later). Also we can figure out whether the person was running or walking or standing or carrying something by a foot print. 

Step 8: Finger Print Analysis : Materials Needed

You will need: 
  1. Transparent Tape
  2. Cocoa Powder/Fingerprinting Powder
  3. Goat Hair or Camel Hair Brush (Make up brush)
  4. Magnifying Glass
  5. A White Flash Card. 

Step 9: Finger Print Analysis : Step 1

Obtain a fingerprint around your house on glass. You can make one too by simply just pressing your thumb on a piece of glass. 

Step 10: Finger Print Analysis : Step 2

Sprinkle a small amount of black powder or cocoa powder (3-4 grams) on the glass area where the fingerprints were present. 

Step 11: Finger Print Analysis : Step 3

Dust the powder on the fingerprint with the help of a soft brush. (Avoid too much contact of the brush with the piece of glass where the fingerprint is present. This would help in lifting a good fingerprint. 

Step 12: Finger Print Analysis : Step 4

Now using the lifting tape, retrieve the fingerprint. (To make sure that you got the entire print, apply some pressure on the tape, not too much). Place the tapes sticky side down on the white flash card given.  

Observe the fingerprint using a magnifying glass. :)

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