DEVELOPING FINGERPRINTS TECHNIQUES VIRTUAL LAB NAME: DATE: Latent prints are formed when the body’s natural oils and sweat on the skin are deposited onto another surface. Latent prints can be found on a variety of surfaces; however, they are not readily visible, and detection often requires the use of fingerprint powders, chemical reagents, or alternate light sources. Generally speaking, the smoother and less porous a surface is, the greater the potential that any latent prints present can be found and developed. In this virtual Lab you are going to observe different techniques and learn the basic procedures of developing latent fingerprints. 1. Developing Latent Fingerprints with Black Powder Watch the following video: https://www.youtube.com/watch?v=tqFzVfPRd5s&t=147s a) List the tools used in the video to develop latent fingerprints. b) Explain why it is helpful to use a separate sheet of paper. c) How much powder is advised to put on the brush? d) What are some different ways people can use the brush? e) Explain the twirling method: f) Why it is better not to put too much pressure when brushing? g) Explain the steps to lift the developed fingerprints. h) What is a lift card? i) Take a screenshot of the final print on the lift card: 2. Developing Latent Fingerprints with Magnetic Powder Watch the following video: https://www.youtube.com/watch?v=iomWm3_Qvhk&t=1s a) List the tools used in the video to develop latent fingerprints. b) Explain how a magnetic wand works. c) Explain the steps to develop a fingerprint with magnetic powder. d) Why the base of the wand cannot touch the surface where the print is located? e) Why is magnet powder more abrasive? j) Take a screenshot of the final print developed: 3. Developing Latent Fingerprints with Ninhydrin Watch the following video: https://www.youtube.com/watch?v=NuGGQ2XK9RM a) What is the chemical formula of Ninhydrin? b) What did Siegfried Ruhemann discover? c) On what type of surfaces does Law enforcement use Ninhydrin? d) How does Ninhydrin react? e) Why is important to use gloves? f) Explain the steps to develop a fingerprint with Ninhydrin g) Take a screenshot of the final print developed: 4. Developing Latent Fingerprints with Cyanoacrylate (superglue) Watch the following video: https://www.youtube.com/watch?v=R0e8WXkFA64&t=32s a) What is a portable chamber? b) On which type of surface is better to use super glue and why? c) What does cyanoacrylate do on the fingerprint? d) Why do they put warm water inside the chamber? e) Explain the steps to develop a fingerprint with superglue f) Take a screenshot of the final print developed:
