Improving the Stability of Stored Fingermarks on Plastic Bags by Axis Inversion Development

Low Density Polyethylene (LDPE) bags are used to package a variety of legal and illegal products including illicit drugs such as cocaine and methamphetamine. In addition to scientific confirmation of the materials in the LDPE bags, it is often desirable or necessary to determine who has handled them. A primary way that this is achieved is by developing latent fingerprints on the bag. This can be accomplished effectively with a variety of techniques, most commonly: Black Powder Dusting or Cyanoacrylate (CA) Fuming. A challenge arises from the fact that a single kilogram of illicit drugs can wind up packaged into hundreds or even thousands of LDPE bags. As a result, when law enforcement personnel arrest persons for sale and distribution of these and other drugs or other contraband substances, they can be faced with an enormous number of samples to process. This study evaluated Axis Inversion (AXI) Dyeing to develop latent fingerprints on LDPE plastic bags by comparing the durability of latent fingermarks developed by this method with those developed by the common Black Powder Dusting and CA Fuming methods. Under test conditions, fingermarks developed with AXI Dyeing proved more durable than those produced by Black Powder Dusting or CA Fuming.