Download Forensics Ballistics

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 The
term ballistics refers to the science of
the travel of a projectile in flight.
 The flight path of a bullet includes: travel
down the barrel, path through the air and
path through a target
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Forensic ballistics is the science of analyzing
firearm usage in crimes.
 Forensic ballistics involves analysis of bullets and
bullet impacts to determine the type.
 Separately from the ballistics information,
firearm and tool mark examinations also involve
analyzing firearm, ammunition, and tool mark
evidence in order to establish whether a certain
firearm or tool was used in the commission of a
crime.
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 One
of the disciplines of forensic science is
firearms identification which is defined by
forensic experts as:
The identification of fired bullets,
cartridge cases or other ammunition
components as having been fired from a
specific firearm.
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 Firearm
identification is also one of the
branches of toolmark identification.
 This is because the firearm, made of a
material harder than the ammunition
components, acts as a tool that leaves
impressed or striated marks on the various
shell casings and other ammunition
components with which it comes into
contact.
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And like fingerprints, no two firearms, even
those of the same make and model, will produce
the same marks on fired bullets and cartridge
cases.
 Furthermore, the manufacturing processes and
the use of the firearm leave surface
characteristics that cannot be exactly
reproduced in any other firearm.
 This means that the toolmarks are unique to
each firearm.
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 Another
aspect that people often don’t
know, is that firearms do not normally
change much over time.
 This allows for firearms recovered months or
even years after a shooting to be identified
by forensic experts as having fired a specific
bullet or cartridge case.
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 Most
law enforcement agencies have access
to a forensic laboratory to aid in their
investigations where highly skilled forensic
experts conduct examinations on many
different types of evidence collected at
crime scenes, including on firearms, bullets
and cartridge cases.
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 Firearms
evidence submitted to a lab's
Firearms Section will typically include:
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a firearm
spent bullets
spent cartridge cases
spent shot shells and/or shot
shot shell wadding
live ammunition
clothing
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 Forensic
ballistic experts look at certain
characteristics of firearms that relate to the
bullets fired from them including the caliber
of the firearm and the rifling pattern
contained in the barrel of the firearm.
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 Cartridges
and cartridge cases on the other
hand are examined for similarities in what
are called breech marks, firing pin
impressions, extractor marks, ejector marks
and other named toolmarks.
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 One
of the most important tools in forensic
ballistics is the comparison microscope also
called a comparison macroscope, where
these toolmarks can be compared side by
side and matched or eliminated.
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 If
the firearm is not recovered, and the
crime lab has the marks on a cartridge case
there's yet another approach.
 They can input it into one of the many
databases – similar to CODIS, the DNA
database.
 One of the ballistics databases forensic labs
in the USA use is FBI sponsored Drugfire.
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 The
Firearms-Toolmark Unit (FTU) is one of
many subdivisions of the FBI Laboratory
devoted to a specific discipline of forensic
science.
 They use Drugfire, an automated, national
computerized forensic firearms identification
system that integrates, cartridge case,
shotshell and bullet analysis, as well as
electronic firearms reference libraries, on a
single computer platform.
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 Hits
are made when a system user finds a
match between a specimen they added into
the database and a previously filed
specimen.
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