Bloodstain Spatter Terms, Resources, and Training
Over the years there has been some confusion in terminology about the different forms of blood spatter patterns and how they are interpreted. Misinterpretation of this data can lead prosecutors to present evidence to a jury that is then disputed by the defense lawyers and can eventually result in an acquittal. In an attempt to standardize the terminology the International Association of Bloodstain Pattern Analysts (IABPA) has established standard terminology to be used in blood spatter analysis. This information can be found at their web site (see below).
A number of books have been written on the subject, and training courses are available on the various aspect of blood spatter analysis. These include, among others, Bloodstain Pattern Analysis by Thomas Bevel and Ross Gardner; Blood Spatter Evidence, A Step by Step Training Manual for First Responders by Louis Akin; and Bloodstain Pattern Analysis Tutorial by J Slemko. Training programs are run at The Institute of Police Technology and Management.
TV's CSI Effect
Unfortunately, with the current craze of CSI and Forensic Files programs on television, blood spatter has become a key element in evidence that juries expect to see in every homicide case. Just like DNA evidence, the analysis of blood evidence at a crime scene is believed to be a holy grail in determining guilt or innocence. However, this is not always the case. A serial killer or someone that is meticulous about details can commit a horrific crime without producing incriminating blood or DNA evidence. Juries need to be reminded that "absence of evidence is not necessarily evidence of absence." This is all the more reason that and blood evidence at a crime scene must not be compromised since it may play a pivotal role in achieving a successful conviction.
In subsequent articles in this column we will investigate a series of cases where bloodstain spatter analysis played a key role in the outcome of a trial.