A picture is said to be worth a thousand words. What about a camera that can actually have the ability to see the invisible, and more? Chemists from the University of South Carolina are developing a camera that will reveal what the naked eye can’t see. Crime scene investigation is evolving with some of these new techniques becoming available.
This new technique is called multimode imaging in the thermal infrared. This technology uses photographic images in several different ways. It captures hundreds of invisible images in just a few seconds, while illuminating the subjects with pulses of invisible infrared light waves. In addition, some of these images are taken with special filters that can block out certain wavelengths making it possible to block out certain objects in the background. It can actually detect blood that has been diluted to as little as one part blood to 100 parts water. That’s quite impressive.
Michael Mynick, Stephen Morgan and their graduate student colleagues explain that the luminol (chemical used for detecting blood stains and other substances at a crime scene) test has disadvantages for being potentially toxic, can’t detect certain diluted substances, and provide false positives.
One of the most impressive aspects of this type of photo imaging is that it can detect the difference between blood, household bleach, soda, coffee, and invisible fabric watermarks.
The ACS Analytical Chemistry reports further states, “These results indicate that this system could be useful for crime scene investigations by focusing nondestructive attention on areas more likely to be suitable for further analysis.”
It’s very encouraging to read about new and less toxic techniques to help investigators and forensic scientists identify a suspect from the crime scene.