Forensic experts retrieve fingerprints from clothing

The new method will help to recover fingerprint ridge detail and impressions from fabrics — something that has so far proved difficult.

The team used a technique known as vacuum metal deposition (VMD), where small amounts of gold and zinc vapour attach to parts of a surface not covered by fingerprint residue — leaving something akin to photographic negative.

VMD has been around for some time and is already used to detect fingerprint marks on smooth surfaces such as carrier bags, plastics and glass. 

Using a trial-and-error approach, the team investigated how different VMD conditions affected fingerprint retrieval in test swatches of fabric with varying composition and weave.

‘It’s kind of like a reverse pressure cooker. It’s under vacuum but there’s a glass window in it so you can look at the fingerprints developing as the process proceeds. If you go too far, it ends up completely covered and so, consequently, you can’t see the fingerprint — there’s a fine dividing line,’ said Abertay’s Prof David Bremner, who worked on the project.