Part I, which reported on the potential of genipin as fingerprint reagent for paper items, indicates that fingerprints developed with genipin appear as blue impressions on paper, which fluoresce upon illumination with approximately 590 nm light. In determining the optimal conditions for using genipin as a fingerprint reagent, the current study focuses on solvents, concentration, temperature, humidity, and warming regime. The study also identified the circumstances under which genipin could be more advantageous than DFO and ninhydrin as a fingerprint reagent. This article describes the materials and methods used, with attention to solvents and concentration, the pH effect, development conditions, fluorescence observation, reactions with compounds that contain amino groups other than amino acids, a comparison with ninhydrin and DFO, and sequential development. One finding is that the quality of genipin-developed prints is donor-dependent. The study also found three potential advantages of genipin as a fingerprint reagent over the more traditional reagents ninhydrin and DFO. First, genipin produce a combination of color and fluorescence in a single reaction. Second, genipin produces a longer excitation and emission wavelength compared to DFO, which may improve the signal-to-noise ratio on papers that show a natural fluorescence in the 500-600 nm domain, e.g., brown wrapping paper or documents written with inks that contain fluorescent ingredients. The performance of DFO on such papers is unsatisfactory. Third, genipin is a safe, environmentally friendly reagent; whereas, ninhydrin carries potential health hazards. 1 table, 3 figures, and 14 references