2. Discuss how fingerprints on the following surfaces should best be visualized, documented, and preserved

Question

a. Latent fingerprint on a silver-colored butter knife
b. Visible fingerprint (black) on the white wall of a house
c. Latent fingerprint on a large manila envelope
What will be an ideal response?

Answer 1

Answer should include points such as the following:
a. The knife should be collected from the scene, packaged, and transported to the crime laboratory. The latent fingerprint should be visualized with gray fingerprint powder or cyanoacrylate fuming with rhodamine dye. The fingerprint should be photographed with the appropriate methods. The knife with the visualized fingerprint should then be secured for storage. Digital-imaging software can adjust brightness and contrast if necessary.
b. The visible fingerprint should be photographed to create a 1:1 image. The wall cannot be removed and transported, so the photograph will be the document and record of the fingerprint.
c. The envelope should be collected from the scene, packaged, and transported to the crime laboratory. At the laboratory, the latent fingerprint should be visualized with ninhydrin. The fingerprint should be photographed with the appropriate methods. The envelope with the visualized fingerprint should then be secured for storage. Digital-imaging software can remove the background color or any writing obscuring the fingerprint if necessary.