Examination of Firearms Review: 2007 to 2010 - Interpol

three manufacturing processes examined show identifying characteristics
immediately after the production. In some cases it cannot be decided if such
characteristics are identifying or class characteristics, e.g. in the case of
impressions in the indentation edge if only one punch is available from a
production series. Punches produced by milling and cold forming exhibit fine and
complex structures (milling grooves, striation marks and wave-like structures
transferred from the die-head) which are not identifying characteristics because
they appear on several surfaces of punches produced in one consecutive series.
Drug packaging is often being submitted for examination in forensic science
laboratories. Most common examinations in such cases are fingerprints or even
physical match, but toolmarks or manufacturing process marks may also be
examined. Dutton (79) presented a case where morphine tablets packaging (foilbacked
plastic blister packs), found in the possession of two separate suspects,
were linked together by using both manufacturing marks and physical match.
Firearm examiners are also faced, from time to time, with marks originating from
surfaces other than firearms per-se. Haag (80) discuss an old-argued question of
linking cast bullets to the mould that made them. Earlier published works had
raised the issues of carry-over and subclass characteristics on bullets from
consecutively manufactured bullet moulds. Based on the findings of the current
study, the presence of unique damage or obvious individual characteristics can
allow an accurate association of cast bullets to their mould.
Other manufacturing marks on pieces of ammunition, this time – the headstamp
impressions on cartridge cases, were studied by Tidrick and co-authors (81). In
contrast to previous research, that has shown that bunter toolmarks, which are
transferred to each headstamp, are unique and persist for a considerable part of
the production run, this article suggest that bunter toolmark examinations are not
particularly useful for associating or disassociating cartridge cases. According to
the results obtained, at least two different bunter tools were represented in a box
of ammunition and, within a box, a bunter tool may be represented by as few as
one or two cartridges. Often, boxes from the same lot feature common bunter
toolmarks, but identical bunter toolmarks were found in boxes of ammunition from
different lot numbers. Also, identical bunter toolmarks were found in boxes of
ammunition bought in different locations.
Miller (82) reports a case in which it was confirmed that an axe blade was
responsible for producing the marks evident on a damaged door. The application
of the blade at the time the toolmarks were made was determined, and a jig was
specially designed to assist in reproducing the toolmarks as closely as possible to
the manner in which they were produced when the offense was committed.
Consideration is given to the types of toolmarks, tool action, and comparison
techniques employed.
Burda and her co-authors (83) examined cable ties of different make and sizes,
and found that these items may bear manufacturing-processes marks (mould
details, ejection pins details, etc.) that can be used for comparison between
suspect and known ties.
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