A new fingerprinting technique that could potentially detect the diet, race and sex of a suspected criminal is reported in the August edition of Analytical Chemistry (doi: 10.1021/ac070580j). The technique combines commercial gelatine-based tapes (gel tapes) to collect and transport the prints, along with infrared microspectroscopy using an array detector. The array detector allows a chemical map to be imaged.

As well as detecting chemicals related to the individual (high urea indicates a male, low quantities a female), the technique has the potential to identify traces of substances a person has been in contact with, such as gunpowder, narcotics and biological or chemical weapons. The technique will also allow research into how fingerprints change over time and in different environments, potentially enabling the age of a fingerprint at a crime scene to be established.