New information from bloodstains.

The traditional philosophy behind the grouping of bloodstains in the Forensic Science Laboratory is described. It is emphasised that while these blood-grouping methods are highly discriminating in the sense that they may distinguish one person's blood from hundreds, or thousands of others, such information may be of limited value in many crime investigations. The reason for this is that such information does not normally relate to physical features of the individual with which we are all familiar such as sex or age. Recent research work is described in which efforts are being made to deduce from small bloodstains information which indicates the donor's sex, age, ethnic origin and perhaps clinical history.