(1) Lifting Latent Fingerprints

Types of Fingerprints

  • Latent Fingerprints

    • Invisible to the naked eye

    • Require development to become visible

  • Patent Fingerprints

    • Visible prints left in substances (e.g., blood)

  • Plastic Fingerprints

    • Three-dimensional impressions in materials (e.g., chocolate, putty)

Collecting Latent Fingerprints

  • Focus on collecting latent fingerprints from surfaces (e.g., desk).

Tools for Collection

  • Magnetic Fingerprint Powder

    • Used in conjunction with a magnetic wand.

    • The wand picks up and releases magnetic fibers without actually touching the surface.

Process of Lifting Fingerprints

  1. Using the Wand:

    • Depress the end to pick up magnetic fibers.

    • Gently run the wand over the area of interest without direct contact.

  2. Understanding Fingerprint Composition:

    • Fingerprints consist of sweat, oil, and protein.

    • The magnetic fibers effectively latch onto the oil components of fingerprints.

Types of Fingerprint Powder and Tape

  • Selection based on the surface being printed.

  • Tape Used Today: Diff Lift

    • Fold the end to create an easy grab area.

    • Estimate required length based on visible print size (2 to 3 inches recommended).

Applying and Lifting Fingerprints**

  1. Tape Application:

    • Hold the folded end and smooth down the tape onto the print.

    • Ensure to hold the corner to prevent movement while smoothing.

  2. Using a Lift Card:

    • Place the fingerprint tape onto the glossy side of the lift card.

    • Use the back to draw a diagram of the lift's location and include case information.

  3. Final Transfer:

    • Carefully peel back the tape and lay it smooth on the lift card to reveal the collected latent fingerprint.