Promising early results from research undertaken by the University of Abertay Dundee and the Scottish Police Services Authority could lead to fingerprint evidence being obtained from clothing, for use in criminal prosecution. Refining an existing technique that’s been used to successfully recover print detail from smooth objects such as glass and plastic, forensic scientists have managed to create a kind of photo negative of fingerprint impressions on fabric. It’s a bit hit and miss at the moment, but even when clear ridge detail isn’t retrieved, the technique could still prove useful to investigators looking for other evidence.
The researchers used a method known as vacuum metal deposition that’s already been used to recover print detail on smooth surfaces like carrier bags, plastics and glass since the 1970s, but has not previously been applied to fingerprint detection on fabrics.
The fabric is placed in a vacuum chamber. Gold is heated and evaporated and spread in a fine layer over the fabric. Heated zinc is then applied, which attaches to the gold layer where the fabric has no fingerprints, leaving the original fabric to show through where contact has been made.