Fingerprint identification has been used as a key method by law enforcement and forensic experts for over 100 years. Our new method for making invisible fingerprints glow could help the law catch up with the ‘bad guys’.
Sometimes conventional fingerprint dusting is not appropriate
Dusting for fingerprints is a common practice at crime scenes. While police and forensics experts use a range of different techniques, sometimes in complex cases evidence needs to be sent off to a lab where heat and vacuum treatment is applied. This can take valuable time, add to cost and impact on investigations.
Making fingerprints “glow”
Our researchers have devised a new method for finding fingerprints using metal organic framework crystals (MOFs).
The tiny MOF crystals rapidly bind to fingerprint residue, including proteins, peptides, fatty acids and salts, creating an ultrathin coating that's an exact replica of the pattern. Our researchers tested the method on nonporous surfaces including window and wine glass, metal blades and plastic light switches, with successful results.
By adding a drop of liquid containing crystals to surfaces, investigators using a UV light are able to see invisible fingerprints "glow" in about 30 seconds. As far as we know, it's the first time that these extremely porous MOF crystals have been researched for forensics.
Catching the bad guys
Because it works at a molecular level, the method is very precise and lowers the risk of damaging the print. The strong luminescent effect creates greater contrast between the latent print and surface, enabling higher resolution images to be taken for easier and more precise analyses.
The method reduces steps and is done on the spot, which would allow investigators to use a digital device at the scene to capture images of the glowing prints to run through their database in real time.
MOF crystals have a number of benefits in that they are cheap, react quickly and can emit a bright light. The technique doesn't create any dust or fumes, reducing waste and risk of inhalation.
The method could have other valuable applications including new biomedical devices and drug delivery.
CSIRO is now looking to partner with law enforcement agencies to apply the technique. The full research paper can be accessed from Advanced Materials .