Blood Pattern Analysis

Bloodstain patterns present on clothing, weapons and at scenes of crime can yield valuable information

Advances in DNA profiling and the acceptance of DNA evidence can lead to new questions - not whose blood is it, but how did it get there? The bloodstain patterns present (or absent) on clothing, weapons and at scenes of crime can yield valuable information concerning the events that led to the deposition.

Cellmark's BPA scientists use their extensive experience to determine information from BPA which can significantly impact on a case. We use a number of chemical techniques to assist with revealing non-visible blood staining, and for enhancing marks in blood, for example footwear marks, wipe marks and drag marks.

BPA analysis can be carried out at a crime scene by our specialist scene scientists, or in our laboratories where we have facilities to reconstruct scenarios and carry out experiments to simulate possible explanations for the blood patterns found.

Analysis of blood patterns can provide information in a number of ways:

• The bloodstain's point of origin
• The type of "weapon" used that resulted in the bloodstain
• Was there a single blow or multiple blows?
• The position of victim and/or assailant at a scene when blood was shed
• The likelihood of blood being deposited on an offender
• The reconstruction of the sequence of events to determine whether this supports or contradicts statements given by suspect(s), victim(s) or any witness(es).
• To aid the selection of stains for DNA analysis eg identifying likely blood from the offender amongst the blood of a victim.