Four previously unknown amino derivatives of ninhydrin, prepared as potential fingerprint reagents, gave intensive colors upon reaction with amino acids in solution and developed latent fingerprints on paper similar to those from ninhydrin. The 5-substituted derivatives, 5-aminoninhydrin, and 5-dimethylaminoninhydrine also presented direct fluorogenic activity with amino acids and with latent fingerprints. There was no marked effect on the fluorogenic process when Group IIb metal salts were added. 1 table, 4 figures, and 14 references (Author abstract modified)