Forensic Blood Analysis: New Approach To Determine Time Since Deposition Of Blood At Crime Scenes

Until now it has been difficult to determine the age of a blood stain found at a crime scene due the present methods being either insensitive or not being able to determine accurately enough the time period since the

blood was deposited. In a recent study, by the National Centre for Forensic Science at the University of Central Florida, a previously unidentified wavelength effect which shows a significant relationship to the life time of a blood stain has been discovered.

The degree of this wavelength effect allows for more accurate determination of the time since the blood was deposited and it is now possible to differentiate between stains that were deposited minutes, hours, days and months ago. Using the NanoPhotometer™ from Implen the team at the National Center for Forensic Science astablished that tiny bloodstains of only 1μl could be used for this investigation. One of the benefits of the NanoPhotometer™ is that it is portable and therefore may be taken to the crime scene to first of all confirm that the stain was blood and then to determine how long it had been there.

The instrument is perfectly optimised for this forensic application as it may operate from a 12V DC supply if required, has no moving parts for in-field reliability, does not require regular servicing or calibration and requires very little operator training plus of course it provides high performance on low sample volumes (Figure 1).

"Using the NanoPhotometer™ from Implen the team at the National Center for Forensic Science established that tiny bloodstains of only 1μl could be used for this investigation."