This is a report on the achievements and anticipated future applications of a thermal infrared (IR) camera that can rapidly and selectively identify blood stains in ambient lighting without the use of reagents.
With the funding support of the National Institute of Justice (NIJ), chemist Stephen Morgan and his team at the University of South Carolina in Columbus developed the prototype thermal IR camera. The camera, which can be operated by a person with minimal technical knowledge, highlights blood stains by filtering out wavelengths that are not characteristic of blood proteins. The prototype has been refined for forensic use, with complete automation of image processing and enhanced sensitivity. In addition, a novel IR lamp was developed by using a heated alumina emitter for active thermal IR imaging. The principal investigators are continuing to validate the technology in both laboratory conditions and with real-world crime scenes. With further development, the camera could also be used to identify other biological materials, such as sweat or semen, or trace materials. As profiling technologies advance (e.g., low copy number DNA testing), technologies like the IR camera that can find small concentrations of biological materials will become even more critical in crime-scene forensics.