Ninhydrin and its analogues are wildly used to detect latentˆngerprints on porous materials. When the contrast of ninhydrin-developedˆngerprints is not su‹cient, indium chloride (InCl 3 ) treatment has been used to improve their images. For non-porous materials, polycyanoacrylate p-dimethylaminobenzaldehyde (DMAB) method and tris thienyl europium chelate (T.TEC) method have recently been developed in Japan. In this study, we examined the eŠects of these latentˆnger-print detection methods on short tandem repeat (STR) typing. Saliva and blood samples were attached to and dried on copy paper for the experiments of the ninhydrin, 1,2 indanedione, and 1,8 diaza‰uoren 9 one (DFO). Saliva and blood samples were also smeared and dried on glass slides for the experiments of the polycyanoacrylate DMAB, and the T.TEC. DNA was extracted from the samples, quantied by a real-time PCR assay, and the STR typing was performed using the Identiˆl-er kit.Various ninhydrin solutions including the acetone and acetic acid solution tended not to reduce the DNA concentrations, and provided full STR proˆles. Heating by putting an iron directly on the samples remarkably reduced the DNA concentrations for 30 seconds. It was recommended that direct-heating be prohibited and that the