Latent fingerprint detection using non-destructive imaging

Latent fingerprints, the marks left by contact with a surface, have been used by forensic science since the 19th century. Often the fingerprints left on objects of interest are hard to detect with the unaided eye, and they may be only partial prints or of low quality.

The current technique for extracting fingerprints involves applying a powder and removing the fingerprint with tape. This method, however, is destructive of the original fingerprint and may not work well on all surfaces.

Researchers at the University of Pennsylvania have developed a non-destructive imaging technique that can provide high-quality images of fingerprints suitable for forensic analysis without disturbing the original evidence.

Light reflected from a surface is usually polarized at an angle, and this information can be used to perform analysis of surface discontinuities, such as the residue left by a fingerprint. Polarization imaging can help detect fingerprints that would not normally be visible, and do so with a high image quality. Because this technique is non-destructive and non-contact, important forensic evidence can be preserved for future analysis.

• Non-contact, non-destructive technique
• No harsh solvents or toxic powders required
• Preserves evidence for additional analysis