Fingerprinting Could Identify Sex, Diet, and Race of Criminal

With new technology a fingerprint could identify the diet, sex, and race of a criminal according to new research from the August edition of Analytical Chemistry. The new technology works by collecting not only the shape of the fingerprint, but also the chemical residue left behind.

A team of researchers from the Imperial College London's Department of Chemical Engineering, lead by Professor Sergei Kazarian created a technique that allows the someone to collect both the fingerprint and the chemical residue and preserve them for future investigation.

Chemical residues are present on every fingerprint, and consist of only a few millionths of a gram of fluid. Conventional methods of preserving fingerprints destroy this chemical information. Now Professor Kazarian and his team have created a way to preserve this residue for future reference.

The scientists devised a way of using commercial gelatin based tape that provided a simple way of preserving the entire print for chemical imaging analysis. Once preserved, the fingerprints are analyzed using a spectroscopic microscope, where the sample is examined with infrared rays to find the individual molecules that make up the chemical composition.

The information found by the spectroscopic microscope is processed by an infrared array detector. This piece of technology was developed by the United States military for smart missile applications. For this application the array detector maps the residue and builds a chemical image of the fingerprint.

This image acts as a guide from which information can be extracted. Often, the information contained in this guide gives clues to the person's identity, such as specific physical traits that could aid in identification. For example, the amino acids on a person's fingernails could determine if he eats meat. High or low concentrations of urea could indicate a male or female.