Old School Fingerprints Just Don't Cut It Anymore

Fingerprints may seem old school to people today. After all, we've been using them in this country to catch the bad guys for over 100 years. Now there is an all-you-can-read smorgasbord of new and exciting discoveries in fingerprinting that will amaze you! It is no longer a world of loops, whirls, and arches, but one of chemistry, nanoparticles, and physics.

• Fingerprints move. At Abertay University in Scotland, they have discovered that the composition of prints, water, fats, and salts, enable a fingerprint to move. This can lead to knowing the time the fingerprint was left. Using an Atomic Force Microscope, they have been able to use this technology on rough surfaces, which are difficult to lift prints from, and new surfaces such as polymer banknotes.
• The sex of an offender can be determined by fingerprints. At Albany University in New York, forensic scientists heated fingerprints to 40 degrees Celsius to separate amino acids from the print. The samples were treated with a chemical dye that oxidizes to a telltale color, based on concentration. Women were shown to have twice as many amino acids as men. The beauty of this is that crime scene investigators can easily perform the procedure without special training. It works like a diabetes test strip and can be used at the crime scene.

Fingerprints Reveal Condom Usage

• Researchers at Sheffield Hallam University in England, have devised a test that will garner copious amounts of data about a perpetrator. This technology uses Mass Spectrometry Imaging to produce a detailed chemical profile of the offender. A special powder is used and then sprayed with a solvent. This action crystalizes the chemicals in the print. It is sensitive enough to show cosmetics, drug usage, condom usage, coffee, drugs or explosives used by a perpetrator. DNA can't do that, and this technique is even more valuable if there is no DNA match in a database. Truly innovative, this testing will give a chemical profile that will fill in a lot of missing pieces DNA can't.
• Dr. John Bond of the University of Leicester has developed a technology that will alter both fingerprinting and ballistics in one fell swoop. Fingermarks on bullets and explosives after they have been exploded or fired leave behind a subtle corrosion of the metal involved. Two British police departments are using the technique right now, but it is sure to become the cutting edge of crime scene investigation everywhere. The corrosion resists extremely high temperatures, being painted over, or intensive cleaning. The culprit is the salts in fingerprints. When the heat of firing or the explosion occurs, the chemical reaction between the salt and the metal speeds up and makes the corroded fingerprint permanent. To visualize the prints, 2,500 volts of electricity is passed through the test item with a conductive powder sprinkled over it. While the heat is applied the powder sticks to the corrosion, making a print visible.

Corrosion of Cartridges

• Scientists from the University of Surrey have found a quick diagnostic test for the use of cocaine in fingerprints. It paves the way for detecting other Class A substances as well. Using a technique called paper spray mass spectrometry, they have been able to detect benzoylecgonine and methylecgonine which are chemicals produced as someone metabolizes the drug. Traces can still be found even after washing hands. It eliminates a tester's exposure to body fluids and will heavily impact drug enforcement.

Nanoparticles

• Swiss researchers have discovered a way to use nanoparticles in detecting fingerprints that can't be found. When a fingerprint examiner goes into a crime scene, they dust for prints where they think they might exist like doorknobs and window ledges. They can't dust everywhere. The researchers deposited fingermarks onto aluminum foil and then submerged them in a liquid solution containing silicon dioxide (SiO2) nanoparticles which had been treated with a chemical group, made up of carbon, hydrogen and oxygen atoms. A dye was utilized to make the nanoparticles visible."Now that it has been established that a chemical interaction can be promoted between nanoparticles and a specific chemical group within the fingermark residue, this interaction can be further promoted, leading to more precise targeting, increased selectivity and the reduction of background noise," one researcher stated.

It just isn't your grandma's fingerprinting kit anymore. New fingerprinting techniques show that in science, you can't just sit back and use the tried and true methods of the past. There are horizons to conquer in something as simple as the touch of a hand.