Physical Developer (PD) is a silver-ion reagent that reacts with the lipids, fats, and oils that are present in latent print residues. It is a very useful and successful method of latent development and is used last in the sequence of chemical development techniques.
Our Chemical Kit for Physical Developer offers a convenient, complete set of pre-measured chemicals for easy mixing (see below for complete kit component list). We also offer small quantities of hard-to-find components for those who prefer to mix their own solutions.
Physical Developer should always be mixed in absolutely clean glassware and mixing utensils. Never use metal trays or utensils. Always following the mixing instructions supplied with our Chemical Kit for Physical Developer. Only mix the solution when you are ready to process the evidence as the mixed solution has a shelf-life of about 1-2 days.
To develop the latent prints, most items will need to be prewashed by submerging the item into a maleic acid solution to neutralize any alkaline components on the item and then allowed to dry. The item can now be submerged in the physical developer solution. Latent prints will typically develop within 5 to 15 minutes. The item should be air-dried and rinsed with distilled water. After the item has dried, the print should be photographed and kept as evidence. The process can be repeated in the event of low contrast development.
- Maleic Acid – 25 grams
- Detergent Solution – 25 grams
- Silver Nitrate Solution – 25 grams
- Ferric Nitrate – 30 grams
- Ammonium Ferrous Sulfate – 80 grams
- Citric Acid – 20 grams
- Instructions for mixing and processing