Blood-spotting camera to revolutionize CSI
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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, the new
hyperspectral imaging device that can scan for the visible spectrum of
haemoglobin 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 chronology of events more rapidly.
It is believed the technology could also be applied to other fluids, including sweat, saliva and semen, which could also improve conviction rates for rapes and other sexual assaults.
Meez Islam, a physical chemist in the University's School of Science and Engineering, who led the team working on the project, said that identifying bloodstains often posed serious problems. Forensic teams were still working with techniques devised a century ago, and there was currently no effective way of dating blood.
"Often, you go to crime scenes and what appears to be blood isn't blood. Blood on dark backgrounds can be hard to see and there are traces of blood that are not visible to the naked eye. What this does is provide fast, at-the-scene identification of blood and speed up the investigative process, as items do not need to go back to a laboratory to be examined. To use hyperspectral imaging in a way that scans the crime scene for blood also means that the chances of missing a bloodstain are vastly reduced," he said.
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 colour, 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 colour over time, from red to muddy brown, at a known rate, the device is able to put an accurate age to a sample. At present, forensic scientists paint chemicals to areas where they believe blood may be present, hoping to produce a reaction with iron found in haemoglobin.
But failure to locate samples has plagued a number of high profile cases.
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 chronology of events more rapidly.
It is believed the technology could also be applied to other fluids, including sweat, saliva and semen, which could also improve conviction rates for rapes and other sexual assaults.
Meez Islam, a physical chemist in the University's School of Science and Engineering, who led the team working on the project, said that identifying bloodstains often posed serious problems. Forensic teams were still working with techniques devised a century ago, and there was currently no effective way of dating blood.
"Often, you go to crime scenes and what appears to be blood isn't blood. Blood on dark backgrounds can be hard to see and there are traces of blood that are not visible to the naked eye. What this does is provide fast, at-the-scene identification of blood and speed up the investigative process, as items do not need to go back to a laboratory to be examined. To use hyperspectral imaging in a way that scans the crime scene for blood also means that the chances of missing a bloodstain are vastly reduced," he said.
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 colour, 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 colour over time, from red to muddy brown, at a known rate, the device is able to put an accurate age to a sample. At present, forensic scientists paint chemicals to areas where they believe blood may be present, hoping to produce a reaction with iron found in haemoglobin.
But failure to locate samples has plagued a number of high profile cases.
