Crime Scene Survey Camera Study

The NIJ recently made available a final technical report through the National Criminal Justice Reference Service: Day and Night Real Time Signature Enhanced Crime Scene Survey Camera.

The authors Milind Mahajan, Karen Zachery, Weiya Zhang, Andrew Brackley, and Xindian Long - all of Teledyne Scientific & Imaging, LLC - write in the Authors' Abstract:

The goal of this work is to lay down the foundations of an integrated day and night forensic survey camera capable of real time enhancement of targets of forensic interest. The camera collects and analyzes different wavelength and polarization channels using multiple wavelength illumination, including ultraviolet (UV) for fluorescence.

Contrast enhancement techniques that use alternate light sources (ALS) with multiple wavelength filters, off-axis illumination for prints, and fluorescence imaging for bio-fluids, are powerful tools already in use by the forensic community. However the majority of current instruments and procedures require a darkened environment, and pose significant logistical challenges. Our concept of a stand-off multi-spectral camera combined with a compact strobed and gated illuminator can provide:

1) Multiple detection capabilities in a single camera system
2) Ability to operate in presence of ambient light
3) Ability to enhance detection using advanced image processing algorithms
4) Intuitive, nearly real time presentation of the results, overlaid on the scene imagery.

We demonstrated contrast enhancement and improved detection threshold across a wide range of targets. In several cases, our camera was able to capture target imagery (e.g. prints, stains etc.) that was invisible to naked eye as well as conventional color digital camera. Adaptive dynamic range compression and false color rendering were effective in directing viewer’s attention to the enhanced target.

Click here to download the full report.

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