foster + freeman Forensic Science Equipment bench-mounted system for the examination of latent fingerprints treated with anti-Stokes fingerprint powders stimulated by IR laser Anti-Stokes Visualisation a novel treatment for the ultra-high contrast examination of latent fingerprints When latent fingerprints are located on material with multi-coloured backgrounds, standard treatments may not produce clear prints because of background interference. Even standard fluorescent powders and stains may fail if the background itself fluoresces. Treatment with the new anti-Stokes powders can overcome this problem. As these powders produce visible fluorescence when illuminated with invisible near infrared light, latent prints that have adsorbed the powder can be seen while the background, reflecting only infrared light remains invisible - rendering the latent prints clear of background interference.

A bench-mounted Class 1 laser viewing enclosure for the stimulation of infrared activated anti-Stokes fingerprint dusting powders, the Crime-lite ASV renders high contrast fingerprints with no background interference. Anti-Stokes powders, also known as up-convertors, are a relatively new form of fingerprint powder that absorb invisible infrared radiation and re-emit the energy at visible wavelengths, a process that is the reverse of standard Stokes-shifted fluorescence. Excellent results can be obtained with fingerprints on 'busy' multi-coloured backgrounds and on backgrounds which fluoresce...