I have just read Grant’s blog post comment about blood pattern work that has been completed recently regarding the distribution of blood patterns at a scene and how they can (or can’t in many instances) be interpreted. The new work could help with interpretations in cases where it hadn’t been possible previously.
The problem with blood spatter is that, in general, people think it is easy to interpret. It’s like footwear marks – everyone knows what blood looks like and what footwear soles look like. This familiarity instills a false knowledge of these evidence types whereas in fact they are both very complex. Footwear in particular was recently the subject of major criticism and review in England & Wales due to a Court of Appeal Ruling in the case of R v T.
In blood pattern work, one of the main irritants is reference to “splatter” when the correct term is “spatter”. However, spatter relates to specific sorts of blood distribution; examination of blood at scenes is generally referred to as blood pattern analysis or BPA.
BPA requires specialist training and, preferably, a lot of casework experience. It’s not like you see on CSI Miami and similar programmes and it would be a mistake to think that it is. For example, I was shocked and appalled to see a senior barrister using a printout from Google on blood patterns in order to cross-examine an expert witness during a trial. The offending Google document was waved around in Court and the judge decided in the end that the barrister shouldn’t be using it because the Google document involved arterial spray (which can be voluminous and travel considerable distances) when the case in hand had nothing to do with arterial spray.
As with footwear marks, the devil’s in the detail when it comes to BPA. Any research that can make it more reliable to interpret will, I’m sure, be welcomed, as long as the method is tried and tested before it reaches the court room.