FS 161 Lecture Notes - Lecture 9: Dermis, Riboflavin, Reagent

• School: SJSU
• Department: Justice Studies Department
• Course: FS 161
• Professor: Mary Juno

Document Summary

Three forms of fingerprints: patent: visible residue print, plastic: 3d impression made in soft material latent: deposition of latent print residue present on frs. Recognition of fingerprint evidence: training and experience, knowledge of human behavior, logic, points of entry, weapons, objects moved or disturbed, varies case to case, oblique lighting. Developing latent prints: basic concept is to apply reagent that will react with one of remaining constituents to make print visible, generally, use powders for smooth, non-porous surfaces, use chemicals for porous surfaces. Latent print residue (lpr: composed of several chemicals exuded through pores at the fingertips, primary component is sweat, other components (longer-lasting), amino acids, glucose, lactic acid, peptides, ammonia, riboflavin, proteins, lipids ix. Surfaces: porous, non-porous, problem surfaces, textured, electronics, vinyl (cars, money, plastic. Powder: different colors, oldest and least sophisticated method, use on non-porous material, best when used in conjunction with super glue fuming, over 85% of fingerprints developed with black powder.