Chemical reagents for the development of latent fingerprints. I. Scope and limitations of the reagent 4-dimethylamino-cinnamaldehyde

In view of the experimental results, ninhydrin seems to be the more general and versatile reagent for the development of latent fingerprints on paper. However, DMAC would be preferable for the quick development of relatively fresh (up to 72 h) fingerprints when the application of heat is forbidden or otherwise impossible (for example, on a sheet of paper wrapping an explosive). Under such circumstances the use of an aerosol container would be recommended. Among the various constituents of human perspiration, urea is apparently not as dependable a substrate for the development of latent fingerprints as are amino acids and peptides.