Dutch crime lab develops fingerprint aging process

The Netherlands Forensic Institute (NFI) has figured out how to determine the age of a fingerprint. What day a fingerprint was left at a crime scene, for example, can be answered some time next year. Marcel de Puit, fingerprint expert of the NFI, says that the police often ask whether fingerprint dating is possible. The verification of a certain date when tracing a crime scene for prints, can help in criminal court cases. It can verify the honesty in dishonesty in statements, for example. The NFI has developed a method to ascertain how old a fingerprint is. A fingerprint is a mix of sweat and skin oil. These prints are full of proteins, amino acids, cholesterol and squalene. De Puit and his colleagues study how cholesterol and squalene react to temperature and light. "If we discover a fingerprint on, for example, a firearm, we make a photo of it to compare to a fingerprint from the database. Then we take the print from the firearm and look at how cholesterol and squalene have developed themselves." To establish that, forensic investigators have to know what kind of circumstances the firearm was found in. If it was lying in the sun, then the result would be different than if it was lying in the snow. By compiling such information, it can be determined whether someone was present at the scene of the crime. This procedure has to happen within 15 days of the print being placed, otherwise the results will be untrustworthy. De Puit hopes that his British colleagues and the FBI will corroborate the NFI's findings, so that this new technique can be put to use in the near future. Toxicologists from the NFI are also working with De Puit on developing a method to gather information about the 'donor's metabolism. "Fingerprints can tell if you've used cocaine, or ate many croquettes. For a judge, it can be important to know if you were under the influence during a crime."