The corpses of murder victims could betray the identity of their killers thanks to a new technique that can capture even faint fingerprints left on a body.

The method makes use of surface enhanced Raman spectroscopy (SERS).

This involves firing a laser beam at a material, allowing its composition to be identified from the wavelengths of light scattered. SERS can also be used to image the distribution of a substance in a material.

Spotting a fingerprint involves applying a solution containing silver nanoparticles to the skin. SERS is then used to image the silver, which sticks to skin secretions. In the process, any fingerprints present are revealed.

The Oak Ridge National Laboratory in Tennessee, which developed the technique, is now trying to build a hand-held SERS scanner for use at crime scenes.