ABSTRACT
Porous substrates are absorbent and are therefore permeable to liquids and gases. Paper, cardboard, and unfinished woods are examples of porous items. Since porous items are absorbent, latent prints are absorbed into the fibers. The water in the eccrine sweat evaporates, but the remaining lipids, amino acids, and other components are bound to the fibers. Most porous processing reagents react with the amino acids in latent prints. In this laboratory exercise, latent prints are developed on a porous item using the three most common porous processing reagents: indanedione, DFO, and ninhydrin.
