A camera that can detect and date blood traces is set to revolutionize the science of crime scene investigation.
Long considered the "holy grail" by forensic experts, a new hyperspectral imaging device that can scan for the visible spectrum of hemoglobin could dramatically speed up police inquires, lead to more convictions and reduce the number of miscarriages of justice, its creators have claimed.
A prototype built by researchers at Teesside University has demonstrated extraordinary levels of laboratory accuracy.
Month-old blood samples can be dated to within a day, while fresh traces have been pinpointed to within an hour of their being taken, potentially helping police to establish a time of death immediately — a process which at present can take several days — and allowing detectives to build a more rapid chronology of events.
The new technology, which will be unveiled at a forensic science conference in Manchester next month, uses a liquid-crystal tunable filter and is able to offer immediate results. The filter works by isolating different wavelength bands of color, so that it can detect blood against other similar-looking substances or in hard-to spot locations such as on red clothing, carpets or furniture.
Because blood changes color over time, from bright red to muddy brown, at a known rate, the device is able to put an accurate age to a sample. 
Source: The Independent