Ardrox Dye Stain—Aqueous Premix
This fluorescent spray is designed for enhancing latent prints that have been developed with cyanoacrylate. It provides excellent ridge detail when the latent print is saturated with Ardrox. Prints fluoresce yellow/green when viewed under a light source (Evident).
Basic Yellow 40 Dye Stain
Basic Yellow 40 Dye Stain is designed to enhance latent fingerprints developed with cyanoacrylate on non-fluorescent, multi-colored surfaces.
Figure 5.46 Results of DFO (Courtesy of Johan Bravo).
Prints fluoresce bright yellow/green between 365 nm and 485 nm with a forensic light source or a UV light (Evident).
Crystal Violet (Gentian Violet)
Crystal Violet (Gentian Violet) is commonly used for developing latent prints on the adhesive side of virtually all types of tape. A simple solution of Crystal Violet and water will produce impressive results. Crystal Violet may be applied by either dipping or brushing the solution onto the adhesive side of tape (Evident).
Sticky Side Powder®
These techniques are used on sticky surfaces. The most common type of surface that these techniques apply to are adhesive tapes (masking, duct, packaging). Gentian violet is used by dipping the item into a bath of the material. Sticky Side Powder may also be used in a bath, or by painting the adhesive surface. Both techniques involve multistep processing when examining tape. Tape has a shiny side, which should be processed for fingerprints before applying either technique. Appropriate safety gear is a must when using either of these techniques. As an example, should Gentian violet contact the skin, the skin will turn purple almost immediately. This is a reaction to the amino acids in the skin. The reaction will not come off quickly. It must wear off. Again, proper safety procedures must be undertaken when utilizing fingerprint development techniques.
Figure 5.47 Sticky side technique for the sticky side of tapes. Magnetic powder to be used on the nonstick side of tapes.
Small Particle Reagent (SPR) is a commonly utilized method to develop latents on wet or difficult surfaces such as rusty metal, rocks, painted concrete, textured glass, heavily oxidized vehicle paints, and sticky soda cans. It particularly excels in processing vehicles that are wet due to rain or dew.