Tool Kit: Developing Latent Prints

Searching for and lifting latent prints is one of the oldest forensic techniques—but new and modified technology is always being developed. Here are a few products that make it easier to find, develop, and lift latent prints.

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Development Equipment

The TFD-2 from Foster + Freeman is an automated, high-throughput device capable of developing fingerprints on large quantities of documents. Evidence is placed on the motor-driven conveyor and passed through the TFD-2 optimized heating element. The action of briefly raising the temperature of the document causes a chemical reaction between the latent fingerprint and the paper’s surface, producing a fluorescent by-product that can be seen under intense visible light. The process of thermal development can be used in the laboratory or at the crime scene and offers the crime-scene investigator many advantages over traditional methods of fingerprint development. www.fosterfreeman.com
Caron’s Fingerprint Development Chambers are designed to accelerate DFO, Ninhydrin, and other fingerprint-development processes. By precisely controlling conditions of high temperatures and high relative humidity, fingerprints are detected at a faster rate and with better clarity. The Caron fingerprint chambers are available in two sizes: 5 cu. ft. (benchtop) and 25 cu. ft. (reach-in, floor-standing). To learn more, visit: www.caronforensics.com
The Crime-lite ASV is a benchtop viewing enclosure for the stimulation of anti-Stokes fingerprint dusting powders. This photoluminescent process is the reverse of standard fluorescence. Instead of short-wavelength light being converted to long wavelengths, the anti-Stokes effect uses invisible infrared illumination and converts it to shorter wavelengths that are visible to the eye. This almost completely eliminates the background, leaving only the fingerprint visible. This is useful for prints on “busy” backgrounds and on materials that fluoresce at similar wavelengths to common fingerprint treatments. www.fosterfreeman.com

Imaging

The UVCorder from Oculus Photonics is a digital near-ultraviolet camcorder that can image many types of patent fingerprints that are barely visible to the unaided eye, particularly if the contamination is blood, dirt, or an oily substance. The image quality is often superior to RUVIS, since the UVCorder’s imaging sensor is a CCD rather than an image intensifier. While the UVCorder is not suitable for purely latent prints, there are many examples of the device imaging faintly visible patent prints. The UVCorder consists of a Canon Vixia Camcorder equipped with the Canon advanced accessory shoe, upon which is mounted a special ultraviolet camera module. Live images are displayed on a 2.7-in. LCD screen. www.ultravioletcameras.com

Develop, Dust, Lift

The new ZAR-PRO Fluorescent Blood Lifting Sheet from Arrowhead Forensics allows the user to clearly and effectively examine latents and impressions that otherwise would be unidentifiable due to background patterns and colors. The lifting sheet is ideal for large or immovable objects that cannot be brought back to the lab for analysis. Lifts are permanent and cannot be smeared or smudged. www.arrowheadforensics.com
Chem Print from Criminalistics, Inc. contains a special formulation that allows deep penetration into porous surfaces such as papers, fabrics, and walls. It reveals absorbed prints where traditional powders and fuming methods fail. The development of freshly applied prints occurs within minutes; older prints develop in hours. The product contains no acetone and does not destroy inks or printing on most documents. www.criminalisticsinc.com
Previously, the only way to dust for latent prints was to apply powder with a variety of brushes. Lighting Spray Aerosol Fingerprint Powder makes it possible to apply fingerprint powder by spraying the suspect area with a controlled, consistent application of powder. This unique application method makes it simple for crime-scene investigators to successfully lift clean prints from a variety of surfaces. http://goo.gl/QdhMR

 

 
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