Appendix A: Techniques/Developers

Technique

Reaction

Su rfaces/Substrate/U sage

Tests for Fingerprints

Physical powder dusting

Magnetic brush powder

Adherence to oils and water residues of print

Smooth, nonporous surfaces; metals, glass, plastic, tiles, and finished woods Porous surfaces such as woods, skin, paper

Oblique lighting and photography

Natural residues of fingerprints

Smooth and nonreflective surfaces

Laser/ALS

Luminescent material in fingerprint residue

Smooth, nonporous, or slightly porous surfaces

X-ray

Adherence of lead powder to fingerprint residues

Smooth, nonporous, and slightly porous surfaces such as human skin

Vacuum coating

Adherence of gold, silver, or cadmium to fingerprint residues

Smooth surfaces such as plastic films, polyethylene, and paper

Chemical iodine fuming

Chemical interaction of iodine with fatty acids and lipid in residue

Smooth surfaces such as paper and human skin

Ninhydrin/DFO (1,8,- diazafluoren-9- one)/physical developer

Chemical interaction with amino acids, peptides, and proteins of residues

Paper, cardboard, unfinished wood

Super Glue (cyanoacrylate ester)

Chemical reaction with amino acids and water molecules

Plastic, metal, glass, cloth

Gentian violet

Sticky Side Powder

Chemical reaction

Tapes, adhesive surfaces

Technique

Reaction

Su rfaces/Substrate/U sage

Small Particle Reagent (SPR)

Physically adheres to lipids and fats

Sticky surfaces, wet surfaces

Ardrox Dye

Stain—Alcoholic premix

It provides excellent ridge detail when the latent print is saturated with Ardrox. Prints fluoresce yellow/green when viewed under a light source (Evident)

This fluorescent spray is designed for enhancing latent prints that have been developed with cyanoacrylate

Basic Yellow 40 Dye Stain

Prints fluoresce bright yellow/green between 365 nm and 485 nm with a forensic light source or a UV light (Evident)

Basic Yellow 40 Dye Stain is designed to enhance latent fingerprints developed with cyanoacrylate on non- fluorescent, multicolored surfaces

Crystal Violet, (Gentian Violet)

Crystal Violet may be applied by either dipping or brushing the solution onto the adhesive side of tape (Evident)

Commonly used for developing latent prints on the adhesive side of virtually all types of tape

1,2-Indanedione

Reagent

1,2-Indanedione Reagent reacts with the amino acids in fingerprint residues and produces fluorescent products that render latent prints visible (Medtech Forensics)

1,2-Indanedione Reagent is a chemical alternative for DFO in chemical processing for latent prints on porous surfaces and is generally utilized prior to processing with ninhydrin

MBD

MBD is a dye stain consisting of MBD dye, 4-(4-

methoxybenzylamino)- 7- nitrobenzofuran, in a mixture of organic solvents

MBD has been noted to be an excellent dye for cyanoacrylate-developed prints on nonporous objects

Nile Red Dye Stain

Nile Red is fluorescent when exposed to a forensic light source between 450 nm and 560 nm, making it ideal for use with a wide variety of forensic light sources (Evident)

Nile Red Dye Stain is often used after cyanoacrylate processing on multicolor surfaces

Technique

Reaction

Su rfaces/Substrate/U sage

Oil Red О (ORO)

Oil Red 0 (ORO) is a lipid stain which is used for enhancing latents produced by the lipids commonly found in foodstuffs, oils, cosmetics, and other fatty substances

Oil Red 0 has been found to be particularly useful in revealing latents on porous surfaces that have been wet, a process that normally removes the amino acids, salts, etc., which are the basis of conventional chemical processing methods

R.A.M. Dye

Stain—Rhodamine, Ardox, and MBD

R.A.M. Dye Stain is a fluorescent stain mixture of Rhodamine 6G, Ardrox, and MBD. Use R.A.M. with a forensic light source after processing with cyanoacrylate

Particularly useful in the enhancement of cyanoacrylate developed prints on plastic bags. R.A.M. enhanced latent prints are visualized between 415 nm and 530 nm, making it ideal for use with a wide variety of forensic light sources. Provided as a 32 oz. premix bottle or concentrate. Mix concentrate with 1 L of solvent (Evident)

Rhodamine

Rhodamine Premix is a dye consisting of Rhodamine 6G dye in a mixture of organic solvents

Rhodamine has been noted to be an excellent dye for cyanoacrylate developed prints. Longwave UV, Laser, or ALS is a suitable light source in order to visualized dyed prints (Medtech Forensics)

Leucocrystal Violet

Leucocrystal Violet is commonly used to enhance bloodstained fingerprints and footwear impressions

Leucocrystal Violet will not enhance a print composed solely of normal latent print residues, so it is used only in cases with blood- contaminated impressions. LCV is nearly colorless when first mixed, but is

Technique

Reaction

Su rfaces/Substrate/U sage

oxidized by the catalytic action of hemoglobin in the bloodstain, and will convert to a blue- colored solution, which will then stain the bloodstain

Sudan Black

Sudan Black is a dye that stains the fatty components of sebaceous sweat to produce a blue-black image

Particularly useful on surfaces contaminated with grease, food residue, or dried soft drink deposits. It is also quite useful as a dye stain for cyanoacrylate developed prints. Sudan Black may be used on nonporous surfaces such as glass, metal, and plastics particularly if these surfaces are contaminated with greasy or oily materials

Tests for Blood Detection

Blue Star

Bluestar Forensic Blood Reagent is a blood enhancement reagent whose purpose is to reveal bloodstains that have been washed out, wiped off, or are invisible to the naked eye

Based on its

chemiluminescence, the unique formula qualifies it as the most effective blood reagent

Fluorescein

Fluorescein causes a catalytic reaction to occur between the hemoglobin in blood and oxygen. This reaction produces a luminescent stain that will luminesce in the dark when excited with UV or ALS

This product is commonly used to detect blood spatter, bloodstained fingerprints, and footwear impressions, as well as, blood evidence which has been concealed or cleaned (Evident)