- 1). Wear latex gloves to avoid adding additional prints to the scene.
- 2). Photograph any visible (patent) fingerprints. Make sure the photo is actual size, meaning a 1:1 ratio to the actual print. If the print is not visible to the naked eye (latent), photograph after you apply powder.
- 3). Pour fingerprint powder onto a sheet of paper. If you place the brush directly into the powder container it can become contaminated, so you should pour out a new amount of powder at each scene.
- 4). Place a brush in the fingerprint powder covering the brush with the powder. Several types of brush and powder are commercially available. A powder that contrasts the most with the surface containing the print like black and grey powders seem to work the best. One British study has shown that aluminum flake powder works best.
- 5). Brush the powder lightly on the surface containing the print.
- 6). Place the tape gently but firmly over the print. Smoothly and evenly press the tape with your fingers or a plastic card so there are no air bubbles. Lift the tape off of the surface, retaining the print outline in powder on the tape. General tape performs best on flat surfaces, but curved surfaces like doorknobs require polyethylene tape
- 7). Place the tape on an evidence collection card, usually measuring 3-by-5 inches. You will need larger cards for palm prints. Use a card color that contrasts with the powder color, such as white card with black powder or a bright color card for grey powder.
- 8). Label the card with the location of the print, your initials and the date collected.
- 9). Place the card in a small plastic bag for protection.
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