1. Fingerprinting Techniques

2. Latent prints – invisible
Use – 1. high-intensity UV light
2. dusting – finely ground powders stick to fingerprint residues, lifted with tape, attached to labeled card – best on fresh prints

3. On nonporous substances
1. Cyanoacrylate fuming (super glue)
- reacts with proteins and fatty acids in print when heated
- item suspended in enclosed fuming chamber w/ warmed water
- glue placed in small container inside chamber & heated
- fumes react with print, print  whitish color

4. 2. Silver Nitrate (AgNo3) solution
- reacts with salts in sweat in print forming silver chloride (AgCl2) – appears black in UV light

5. On Porous surfaces Ninhydrin
- reacts with amino acids in print – turns purple
- spray or dip item in ninhydrin – 48 hours to develop (faster if heated)

6. 2. Diazofluoren (DFO) - paper dipped in DFO for 10 sec, dry, repeat - reacts with amino acids - visible under blue-green light

7. On NonMetal surfaces
Vacuum metal deposition - chamber evaporates gold & zinc - gold attracted to thin layer of tissues left by print, zinc condenses on gold coating and b/t ridges

8. Fingerprint Database Prints – photographed, scanned, digitized
- for comparisons
FBI – Integrated Automated Fingerprint Identification System (IAFIS)