Cartridge Clues
| Published date | 01 July 1935 |
| DOI | 10.1177/0032258X3500800305 |
| Date | 01 July 1935 |
| Author | A. E. Harwich |
| Subject Matter | Article |
Cartridge Clues
By
DETECTIVE-CORPORAL
A. E. HARWICH,
F.R.M.S.
Palestine Police Force.
QNL
Y too often in Palestine the sole clue found at the
scene of a murder is a cartridge case ejected from the
weapon that fired the fatal shot. Whereas formerly it was
only possible to determine the type of fire-arm used, one is
now able to tell definitely whether that cartridge has been
fired from any particular rifle which may later be seized from
a suspect. A fire-arm is too valuable a possession in Palestine
to be thrown away or destroyed after the commission of an
offence and is invariably discovered later hidden in or near
the house of the
murderer-if
not on his person.
The
scientific
evidence in the following case is of unusual interest, as showing
how much can be done in the way of linking up different
offences committed by the same person using the same fire-arm
for each offence.
Abrief description of the method adopted might be of
interest.
The
bolt-face and the striker tip of every fire-arm
is either finished off by hand with a file or by a machine,
according to the shape and size of the extractor or other raised
areas on the surface; consequently, there are no two bolt-faces
bearing similar striations.
The
bolt is of hard steel, whereas
the base of the cartridge is brass and the percussion cap of
soft copper. When the cartridge is fired, a pressure of about
18 tons to the square inch (rifles) is generated in the
breech:
the base of the cartridge is forced against the bolt-
face and the striations on the latter are embossed on the
copper cap, in much the same manner as soft sealing-wax
takes the impression of a seal of harder material. Every
expended cartridge, therefore, carries with it the thumb-mark
of the particular fire-arm in which it was fired. Needless to
say any damage, marks of erosion or corrosion on the bolt-
face are also transmitted in negative form to the cartridge.
28~
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