Examination of Firearms Review: 2007 to 2010 - Interpol

Suzuki et al [14] described the investigation of a murder case the suspect
stated that he had found the victim's body when he broke into the crime scene
in order to commit theft. Consequently, the crime scene was reconstructed in
accordance with the suspect's confession, and the suspect's behaviour was
simulated according to the confession. In order to assess the reliability of the
suspect's statement, the distribution and number of characteristic fibres
collected in the simulations and during the actual investigation were compared
which revealed a significant difference in the numbers of fibres found at each
area of the victim's body, the mattress, and the blankets. The difference in the
number of fibres found close to the victim's head was particularly significant.
The findings were presented as evidence in court and the defendant was
subsequently found guilty of murder.
Sulkava [15] reported on a murder case where unusually the target fibres in
question, were blue denim. The victim in this case was a hermit who
possessed no clothing containing fibres of this type. The unusual
circumstances of this case are discussed as is the role of the fibre evidence in
combination with other evidence types in securing a conviction. The case
illustrates the context sensitivity of forensic casework and how a fibre type
normally considered of no evidential value proved crucial in the investigation.
It is interesting and gratifying to note that in each of the above cases of
homicide, the fibre evidence was used early on in the investigation as an
intelligence tool - exemplifying their value as a primary application tool, rather
than a ‘last ditch’ possibility (as is often perceived by some investigators).
Fibre evidence continues to be used routinely in the investigation of a number
of cases involving motor vehicles, where there is dubiety over who was driving
the vehicle in question. In order to correctly identify who was driving at the
time of a traffic accident or vehicle theft, as many seats as possible from the
vehicle(s) should be examined for fibre traces.
Majdic [16] described a case illustrating the importance of determining the
relative distribution of fibres from target garments on each of the seats of a
vehicle. The case clearly demonstrates it is not sufficient to consider only the
fibre findings from the driver's seat in order to answer the specific question
and emphasises the problems encountered through poor submission strategy
resulting from attempts to cut costs/ corners.
Whilst the distribution of fibres transferred to vehicle seats can be helpful in
identifying the putative driver, the use of examinations for fibre plastic fusions
remains the method of choice for this type of investigation. Schaich [17] and
Irwin [18] presented case studies exemplifying the power of this approach in
unequivocally identifying the driver of a vehicle at the time of the collision. The
presentation by Irwin [18] was particularly interesting, in that it illustrated how
approaches using blood distribution in these circumstances can produce the
wrong result.
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