Abstract
Lasers are widely used in criminal investigations. Fingerprints are one of the most important clues
among forensic samples taken in the field. Although fingerprints are detected on various substrates,
fingerprints cannot be visualized in some cases when the fluorescence of the substrate is strong.
Therefore, we performed fingerprint visualization with a pulsed laser by time-resolved spectroscopy. We
also examined the aging of fingerprints and fingerprint components. The fingerprints were visualized
using various lasers such as UV, visible, IR, ns-pulsed, fs-pulsed, and CW. In addition, the application
of lasers to forensic samples other than fingerprints was described in this paper.
