Imagine being able to determine race, sex, and other features of a person just from chemical residues from their fingerprint!
From Science Daily:
Professor Sergei Kazarian from Imperial College London's Department of hemical Engineering, has devised a technique which collects fingerprints along with their chemical residue and keeps them intact for future reference.Reference: "Spectroscopic Imaging of Latent Fingermarks collected with the aid of gelatine tape" Journal of Analytical Chemistry, 1 August 2007. Anal. Chem. 2007, 79, 5771 -- 5776.
In many cases, this information is enough to determine valuable clues about a person beyond the fingerprint itself. It could potentially identify traces of items people came in contact with, such as gunpowder, narcotics and biological or chemical weapons.
Chemical clues could also highlight specific traits in a person. A strong trace of urea, a chemical found in urine, could indicate a male. Weak traces of urea in a chemical sample could indicate a female. Specific amino acids could potentially indicate whether the suspect was a vegetarian or meat-eater.