ABSTRACT
Latent friction ridges are typically comprised of chemicals secreted by the eccrine and sebaceous glands plus miscellaneous contaminants [1]. The pores of the eccrine glands are located directly on the friction ridges, whereas the sebaceous materials are transferred to the €ngers by frequent contact with the face, neck, and scalp where the sebaceous glands occur in high density. Subsequently, friction ridge residues are comprised of the chemicals contained in the sweat and sebum. The composition of eccrine sweat is in excess of 98% water but it also contains a wide variety of inorganic (e.g., salts and trace elements such as magnesium and zinc) and organic (e.g., amino acids, proteins, and lipids) material. For friction ridge detection, the compounds of primary interest within sweat are amino acids such as serine, glycine, ornithine, and alanine, which react with ninhydrin [2], 1,8-diaza’uoren9-one (DFO) [3], and 1,2-indanedione [4] to produce colored and/or ’uorescent reaction products that can be visualized and recorded. Sebum composition shows much variation between individuals but the major lipid components have been identi€ed as fatty acids
CONTENTS
14.1 Introduction ........................................................................................................................ 381 14.2 Arson ................................................................................................................................... 382
14.2.1 Introduction ............................................................................................................ 382 14.2.2 Soot Removal Techniques ..................................................................................... 387 14.2.3 Effects of Flammable Liquids on Latent Friction Ridge Impressions ............ 393 14.2.4 Recovery of Latent Friction Ridge Impressions ................................................. 395 14.2.5 Recovery of Friction Ridge Impressions in Blood ............................................. 398
14.3 CBRNE ................................................................................................................................. 401 14.3.1 Introduction ............................................................................................................ 401 14.3.2 Chemical Contamination ......................................................................................402 14.3.3 Biological Contamination .....................................................................................405 14.3.4 Radiological ............................................................................................................ 407 14.3.5 Decontamination ...................................................................................................408 14.3.6 Explosives ................................................................................................................ 412
14.4 Conclusions ......................................................................................................................... 414 Author ........................................................................................................................................... 414 References ..................................................................................................................................... 415
(37.6%), wax esters with diglycerides (25%), triglycerides with monoglycerides and cholesterol esters (21%), squalene (14.6%), and cholesterol (3.8%). These sebaceous components are valuable for latent friction ridge detection because they persist, even in the presence of water, and can be detected by a wide variety of physical and chemical techniques such as powders [5], physical developer [6], iodine [7], small particle reagent (SPR) [8], and cyanoacrylate (CA) [9].
