New UV/IR light source lets investigators extend crime scene searches Beyond the Visible

 

infrared ultraviolet light source for CSI 

The new Crime-lite 42S UV/IR crime scene search kit provides investigators with a powerful search tool for the detection of blood, fingerprints, body fluids and other forensic evidence on difficult backgrounds that may be difficult to see in the visible.

A fully portable battery powered system, the Crime-lite 42S UV/IR uses reflected ultraviolet and near infrared light, imaged with a UV-IR sensitive camera, to detect evidence that cannot be seen in normal visible light.

Originally designed as a portable solution for examiners wishing to use the new generation of Crime-lite Infrared light sources at the crime scene, it was quickly recognised that by adding both UV and IR to the system, through the inclusion of a Crime-lite 42S UV/IR dual waveband light source, it would be possible to produce a unique search tool for viewing evidence beyond the visible at both ends of the spectrum.

Different substrates reflect and absorb UV and IR illumination in different quantities and while this cannot be seen by the naked eye it can be observed using a UV-Vis-IR sensitive camera. Using the Crime-lite 42S UV/IR kit, examiners are able to alternate between examination wavebands (adjusting the integrated camera filter accordingly) to view the differing amounts of UV and IR light that is reflected back from surfaces under examination. Differences in light reflectance and absorption can create contrast between substrates that may not be visible to the naked eye, for example:

Blood stains
Dark fabrics reflect IR wavelengths and appear white when viewed using the UV-Vis-IR camera. Blood stains absorb IR and can clearly be seen as dark patches.

Body Fluids
Many organic materials, including body fluids, will absorb UV, for example saliva appears as a dark patch against inorganic laminate floor, which reflects UV and appears white.

Body Art
Visibility of tattoos can be greatly improved using IR illumination; this can be particularly effective when using these distinctive markings to identify charred remains.

Other applications of the Crime-lite 42S UV/IR crime scene examination kit include the examination of bite marks, detection and improved visualisation of tool marks, shoe prints and scuffs, and the examination of painted surfaces for the detection of freshly applied paint and or evidence hidden below paint.

The Crime-lite 42S UV/IR kit is a simple to use and highly effective CSI tool. For further information contact Foster + Freeman

 

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