fingerprinting lab new

Unit: Fingerprinting
Lab: Developing and lifting latent fingerprinting
Surface type & lifting method:
Hard, nonporous: glass, tile, & lab bench
 Powder: black, magnetic, or fluorescent
 Super Glue (cyanoacrylate) Fuming: (metals, plastic)
Porous: paper
 Iodine Fuming: solid crystals will (sublimate) change to vapor & adhere to oil & perspiration
Magnetic powder
Fingerprint brushes
Super Glue fuming tank
Soda can
Fluorescent powders
Hand lens
Safety glasses
Aluminum powder
Cyanoacrylate (Super Glue)
Glass (slide or beaker) Gloves
Fingerprint cards
Procedure: For use with all powder types
First: Cover the lab bench with Newspaper!
Dusting a Fingerprint:
1. Wipe you forehead or hair with one finger. USE A DIFFERENT FINGER FOR EACH PRINT.
2. Place a print on a nonporous surface. (desk, glass slide, or beaker)
3. Use fingerprint powder to dust the fingerprint.
4. Dip the brush in the powder, tap or twirl the brush over paper to remove excess powder.
5. LIGHTLY dust the slide or print source. Too much powder will ruin a good print.
6. Distribute the powder evenly.
7. Too much brushing will ruin the print.
Lifting a Fingerprint:
8. To lift the print from the slide to data table, unroll about 4 inches of tape and place it on the print, be
sure to remove air bubbles.
9. The print can be removed by pulling up on the roll end of the tape.
10. Make sure the tape is secure. Cut tape from the roll. This will take practice!!
11. Place lifted print on a fingerprint card or index card to be taped into your lab!
12. Repeat for all required powders.
Procedure to be used when dusting and lifting prints from various surfaces.
For this part of the lab you will be required to choose surfaces that you think will contain latent prints.
1. Dust the surface with the magnetic powder.
2. Use the tape to lift the print and place it on an index card.
3. Label the source of the print and identify the type of powder used to lift the print.
4. Repeat for a total of 2 lifted prints.
Developing Fingerprints with Iodine Fuming
Iodine crystals will easily develop fingerprints on paper. The oily material of the print absorbs the iodine
vapor and produces a violet to purple-brown fingerprint. When exposed to the air, this print will eventually
1. Take a square of white paper: Place the paper on a clean table surface carefully holding only the
edge of it. With your gloves removed, press your thumb directly into the center of this paper.
Do not roll or rock your thumb back and forth.
2. Cut a piece of tape about 1” long and place half of it on the top of the small piece of paper containing
the thumbprint. Carefully open the top of the jar containing a small amount of iodine crystals. Tape
your piece of paper containing your thumbprint onto the underside of the jar lid. Carefully replace the
lid onto the jar. Allow the paper to come in contact with the iodine vapor between 3 to 5 minutes, or
until your print is visible.
3. Once you can see your developed print use forceps to remove the paper from the jar.
4. Immediately take a picture of the print.
Using Cyanoacrylate to visualize prints:
Cyanoacrylate, better known as Super Glue®, is a very practical substance for lifting fingerprints from
metallic surfaces. Prints can be easily lifted from such items as knives, guns, soda cans, plastic
cups, bottles and cd’s.
Procedure: Put on your SAFETY GLASSES!
1. Place 10 drops of Super Glue in an aluminum tray.
2. Place the aluminum tray in the Fuming Chamber.
3. Obtain an empty aluminum soda can, plastic cup, bottle or cd.
4. Place a few fingerprints on the item and hang it in the fuming chamber. Let sit for 10 – 15 minutes or
until prints are visible.
5. Carefully remove the cover of the Fuming Chamber. STAY CLEAR OF THE REMAINING
VAPORS…... Lift the can by its edge and observe the prints, classify and record.
6. Use the powder to lift the prints and tape them to a fingerprint card.
Recording Data:
Put all prints on index cards or fingerprint cards & label. Once completed, you will tape all your prints into
a data sheet. Label 10 points on each print. Remember each created print must be from a different
finger or a different source.
Required Prints:
 Magnetic powder: 2
 Other (white, grey or fluorescent): 2
 Super Glue: 2
Various Surfaces: your choice of surface: 3
 Iodine: 1
Total prints: 10
Data Requirements:
 Lifted prints must be neat, clear, labeled and taped into your data table.
 Your lab data must include all clear readable prints with 10 individual points on each.
All prints must include:
1. Type of surface & source
2. Classification of print (loop, whorl, arch)
3. Lifted print from the different surfaces must include 10 individual characteristics.
4. Developing method.
Latent Fingerprints
Post lab questions
Name ___________________________________________
Must be answered completely.
1. How did a fingerprint developed with any powder compare to an inked print?
2. What were some of the challenges of lifting prints with magnetic powder?
3. What were some of the challenges of lifting prints with the fluorescent powders?
4. What were some of the challenges associated with lifting latent fingerprints versus inked prints?
5. Compare each of the methods of developing fingerprints. Which method do you think is best?
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