Photographs of Cartridge Cases and Bullets
| Published date | 01 October 1939 |
| DOI | 10.1177/0032258X3901200403 |
| Date | 01 October 1939 |
| Author | G. C. Britz |
| Subject Matter | Article |
Photographs of Cartridge Cases
and Bullets
By
LIEUTENANT
G. C.
BRITZ,
South
African Criminal Bureau, Pretoria
AT one time the expert in Forensic Ballistics could give
his evidence in a Court of Law and was not required to
support his evidence by photographic or other illustrations.
Nowadays that kind of expert will find it hard to convince
anyone that his evidence is reliable unless he can show how
he arrived at his conclusions.
In
the event of evidence about the identity of cartridge
cases and bullets it may be difficult to mark minute points
of identity on the photograph in such a way that detail is
not interfered with and yet anyone may check up on the
various points.
In
the accompanying illustrations amethod
is shown which is 'reliable and easy to use.
The
writer has found that for small objects, such as
cartridge cases, the
"Leitz"
large comparison microscope
is the best to use, because of the moveable prism set employed
in its eyepiece component. On this microscope it is an easy
matter to take photographs of identical magnification and
perspective, which is essential
if
success is to be ensured.
Assume that cartridge cases have to be examined. Using
the comparison microscope an examination is made and it
is found that on the base of each cartridge case appear minute
marks of similarity which were made by the pistol in which
they were fired. On the groove edge of the rim of each it
is found that the pistol has left its mark in the form of a scar.
All these marks are similar to marks found on test cartridges
fired in the suspect's pistol.
Photographs are taken as required, and it is found that
only the expert will be able to locate the points of identity
because of their minuteness or similarity to other nearby points.
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