Examination of Firearms Review: 2007 to 2010 - Interpol

smooth impact sites of fleshed and defleshed bones, contradicting the findings
previously published results. The consistently smooth impact sites and rough
fracture surfaces may be useful features in the characterization and reconstruction
of axe and hatchet wounds.
Wong (95) searched for the most appropriate method of preserving and examining
tool marks on cartilage and bone. Guillotine paper cutter was used to cut the
cartilage specimens, while a fire axe was used to chop the bones. Ten different
combinations of preservatives and storage conditions were also compared. Casts
of the tool-marked surfaces, made before preservation, served as a baseline for
comparison. The casts made after preservation were subjected to microscopic
examination, compared to the pre-preservation casts, and scored to evaluate the
performance of the preservatives in their respective storage conditions. The
results obtained suggested that most aqueous solutions stored in a cold
environment were good at preserving the finer accidental tool mark characteristics.
It was concluded that the optimal method involved the immersion of the samples in
a 0.9% NaCl saline solution, frozen storage, air-drying after removal from storage,
and casting with rubber-base polysulfide dental impression material (COE-FLEX
®) for identification work.
The dynamics of knife punctures in cervical vertebra and in tire rubber was studied
by Locke (96). In the course of a murder investigation, a cervical vertebra of the
victim was examined. It was shown that toolmarks present on the cervical vertebra
of the victim had been made by one edge of the swedge of the suspect knife - a
finding that led to further research into the dynamics of a knife puncture. This
research showed that the characteristic “Y” tear observed in a tire puncture is
more than a tear, being two cuts made by the left and right edges of the back of a
wide-blade knife.
Bearing in mind the paucity of articles in the area of toolmarks on bone, Fred
Tulleners of the University of California Davis has reprinted a 1947 article by
Thomas and Gallent (97) regarding the identification of the weapon used in a
murder case. By comparing the toolmarks made by the axe (found in the
possession of the suspect) with the marks made by the weapon on the skull of the
victim it was determined that the axe had been used to commit the offence.
Interestingly, the 1947 includes even statistical evaluation of the results. Other
articles dealing with the characterization of trauma caused by various types of
tools were found to be outside the scope of this Review.
3.6 Evidential Value of Toolmark Examination
Toolmark (as well as firearms identification) examinations have gone through the
same scrutiny as other classic identification areas. The way forensic scientists are
taking the “leap of faith” (98), stating that a questioned mark was made by a
specific known tool (with the exclusion of all others), drew a lot of criticism, mainly
from non-forensic-scientists (99-101, and others). In her commentary on Nichols
(102) extensive article, Schwartz (103) argued again that the AFTE Theory of
Identification is not a valid one, since it is based on the limited experience of each
examiner, that proficiency tests are usually easier and less complicated than
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