ISSUE 53 Expert Witness Journal - Journal - Page 24
Some of the patterns generated by the examples listed
above share some identifying features and often a
complex mixture of patterns is encountered. However, with the use of objective criteria and careful consideration of the contextual and medical information
in the case a sufficiently experienced scientist can form
a reasoned judgement on questions regarding what
activities may have occurred.
Statements/video footage from those attending can be
vital in fully evaluating the findings.
Assaults are often dynamic events consisting of a
multitude of movements and actions of which the individuals involved may have little awareness/recollection. In considering accounts given by prosecution
and defence, it is essential to appreciate that these are
highly unlikely to detail every movement made.
BPA in Criminal Investigations
BPA can be a powerful reconstruction tool - assisting
in building a picture of what may have happened during and after blood was shed. It may also be of use in
answering questions such as:
• What was the position of the victim and offender
and/or objects at the time of bloodshed?
The Defence Review
Forensic Access’ scientists regularly conduct BPA on
items previously examined by the prosecution, items
not previously examined, and scenes and vehicles. We
can also review blood patterns from photographs.
Through our many years of casework experience, we
understand the usefulness of BPA but also the dangers of over interpretation and misinterpretation of
blood patterns.
• How have individuals/objects moved/been moved
through the scene?
• Was there a fight or struggle?
A defence review of any BPA case will look at all the
factors which are critical to the evidence being robust,
balanced and correctly informed.
• What type of weapons were used?
• How many blows, shots or actions occurred?
• Was the offender injured? Which blood is theirs
within the scene?
Case examples:
1. Though not alleged, a defendant’s charge was
increased to include kicking based on the BPA conducted by the prosecution scientist. Our defence review showed that the patterns had been misidentified
and instead of kicking could be more readily explained by the more passive action of blood dripping
into blood already on the ground. This was put to the
Crown scientist and agreed resulting in the kicking
charge being removed.
• What bloodstaining might we expect on the
assailant?
• Has there been an attempt to clean up after the
assault?
The above questions are investigative in nature and
can be particularly useful when there is little information available.
2. Prosecution evidence was that blood patterns in a
vehicle were deposited from an assault taking place
wholly outside the vehicle. This did not align with the
defence case statement. A re-examination of the vehicle and reconstruction of blood trajectories showed
that the Crown’s evidence was incorrect, and part of
the assault must have taken place inside the vehicle.
With cases at trial there will often be defined prosecution and defence positions. In these circumstances
BPA is particularly powerful. The scientist can use
their detailed understanding of the bloodstain patterns in the case, and a knowledge of the mechanisms
which could generate them. They can then apply this
understanding to the differing versions of events put
forward, making a judgement about whether the
bloodstain evidence is more likely given one version
of events rather than another.
3. The Crown scientist reported that the BPA
supported the view that a defendant had assaulted the
complainant as alleged. Our review gathered scene
photographs and body worn video from first responders, not seen by the Crown scientist, and together
with a review of the clothing showed that the bloodstain evidence was in fact neutral, leading to the
Crown scientist re-issuing their report to reflect this.
Limitations of BPA
Understanding what BPA cannot say is as important as
understanding what it can say. The following are some
areas where caution is needed:
Bloodstains cannot be aged purely from their
appearance. This should be considered when assessing bloodstaining at a scene or on clothing where
there might be historical incidences of assault/bloodshed.
Contact Forensic Access
Do you have a case involving BPA or requiring a
scientist to review BPA evidence? Don't miss out on
the evidential opportunities BPA can provide for your
case. Work with our casework management team to
effectively delegate, save time and strengthen your
defence strategy.
Where multiple individuals have bled. Care must be
taken not to assume that certain blood patterns are
from a particular individual without good cause. DNA
profiling should be used to minimise uncertainty.
Contact us at science@forensic-access.co.uk
or (+44) 1235 774870.
Some observed patterns could relate to the actions
of attending paramedics, witnesses, police officers,
crime scene investigators and forensic scientists.
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