Tools of the Trade: Dealing with Unusual surfaces

James McDermott 10/14/13

Tools of the Trade: Dealing with Unusual surfaces. 

       In this article the author, Dick Warrington writes that lifting prints from a surface isn’t that strenuous, even if it’s lifting prints from unusual surfaces. The author states that the only two surfaces water and air are the only surfaces not permitting identification of fingerprints. At first Mr. Warrington goes into detail about multi-textured and multi- contoured surfaces. Starting out broadly the author starts to get into more detail about these multi textured and multi-contoured surfaces and how to lift prints from these surfaces. Polyethylene Tape is used to lift prints from multi-curved surfaces such as light bulbs and doorknobs. This tape works well on these surfaces because it stretches and conforms to the shape of these surfaces without distorting the latent print. Another way to discover prints is to use DIFF-Lift Tape. This tape is 20 times stronger than regular tape, gives much better results. DIFF-Lift molds itself to textured surfaces to get all of the details of the powdered print. It can be used to lift prints from vinyl car dashes, pebble-grained leather, textured plastic, metal, paper, and wood. When getting into Adhesives such as duct tape, masking tape, and mailing labels, it can be developed and lifted, but it’s often quite difficult to do so. The key is to use a specially designed product, called an adhesive side powder, for the job. The adhesive side powder is mixed with equal parts water and dispersing agent until it reaches a consistency similar to thin paint. The mixture is then applied to the adhesive side of the tape or label using an all-purpose brush. After the solution sets for 10–15 seconds, it’s rinsed with water. If it sets too long, it will fill in the background. When you find dust fingerprints and footprints, collect them with an electrostatic dust lifter such as the PathFinder. The PathFinder is a wireless device that can lift prints from most surfaces, including wooden window ledges, carpet, tile, and upholstery. Lastly, a hard surface to investigate is a wet surface. When using a small particle reagent (SPR) it is easy to lift prints. SPR is like liquid fingerprinting powder and can be used on non-porous surfaces. Spray SPR onto wet evidence then rinse with water. The reagent adheres to the latent print. This article is very interesting and informative. Mr. Warrington explains how easy it is to decipher latent prints from any surface.

Posted for J. McDermott by C. Ippolito