Overview of Chemical Tools and Methods

Adhere to both water and fatty deposits. Generally useful on newer prints. Choose powder to contrast with background. Useful on dry, relatively smooth, non-adhesive surfaces. Use after laser fluorescence. Use before Ninhydrin and after Cyanoacrylate. Results may vary with skill. Photograph or lift by conventional methods.

Offer advantages conventional powders don't, but applied the same. Photograph or lift by conventional methods. Useful on confusing or multi-colored backgrounds. UV or forensic light required.

Fumes react with oils and fatty deposits to produce a temporary YELLOW-BROWN reaction. Useful on fresh prints on porous, non-porous, and non-metallic surfaces. Developed prints must be fixed or photographed immediately because reaction will rapidly fade. Use before Ninhydrin and Silver Nitrate.

A fluorescing Ninhydrin analog found to develop up to 2.5 more prints than Ninhydrin. Useful on porous surfaces, especially paper. Accelerate development by applying
controlled heat. Use before Ninhydrin. Also useful to develop weak blood stains. Requires blue light.

Reacts with amino acids to produce a PURPLE reaction called “Rhuemann’s Purple”. Useful on porous surfaces, especially paper. Development time can take up to 10 days, but may be accelerated by applying heat and humidity. Use after Iodine and before Silver Nitrate. Not useful on items exposed to water.

Reacts with the chlorides in skin secretions to form silver chloride, which turns GRAY when exposed to light. Photograph developed prints immediately because the reaction will eventually (and permanently) fill the background. Useful on paper, cardboard, plastics and unvarnished, light-colored woods. Use after Ninhydrin and Iodine. Not useful on items exposed to water.

A silver-based developer which forms a DARK GRAY reaction. Useful on paper, cardboard and unvarnished, light-colored woods. Use after Ninhydrin and Iodine. Successful on items exposed to water.

A suspension of fine molybdenum disulfide particles. Adheres to the fatty components of skin secretions to form a GRAY deposit. Photograph developed prints immediately because reaction product is very fragile. Use conventional lifting methods. Useful on relatively smooth, non-porous surfaces, including wet. Use in place of, or after, physical developer.

(Super Glue) fumes react (polymerize) fingerprint constituents to form a hard, WHITE deposit. Useful on most nonporous and some porous surfaces. Produces excellent results on Styrofoam and plastic bags. Developed prints may be dusted with powders or enhanced with fluorescing dyes, such as Ardrox and Basic Yellow.

Reacts with the proteins found in blood to form a BLACK reaction. Useful only on blood-contaminated prints on nonporous and slightly porous surfaces. It is highly sensitive. May offer successful development of blood prints on dead human skin.

Attaches to plastic print impressions on the adhesive side of tapes. Produces excellent results on light-colored or transparent tapes, including duct tape, masking tape, plastic surgical tape, foam tape, clear and reinforced packing tapes and labels. Process involves wetting tapes.

Special dyes made to fluoresce and bond with print deposits. DFO, a fluorescing Ninhydrin analog, develops up to 2.5 times more prints than Ninhydrin. Useful on porous surfaces
and with Cyanoacrylate. Accelerate development by applying controlled heat. UV or blue light required.