Forensic Ballistics 1word
Forensic Ballistics 1word
Forensic Ballistics 1word
Forensic Ballistics
by:
1.( DEFINITION) In general, or in its broadest sense, the term “ballistics” is defined as the
“science of the motion of projectiles”. Science refers to the scientific study or knowledge : motion refers
to movement or mobility : and projectiles refers to metallic or non-metallic objects propelled from a
firearm. It is a science in itself, because it developed as a result of systematic studies and knowledge,
research and development, training, experience, and education.
In particular, or in its narrowest sense or in brief, and technically speaking, the “ ballistics” refers
to the “science of firearms identification” which involves the scientific examinations of ballistics exhibits
– fired bullets, fired shells, firearms, and allied matters – which have been used in crimes. With the
application of this science, it is now possible, with the use of proper techniques and under proper
conditions, to determine whether or not a certain evidence . . over
Such as the bullet or the shell was fired from a particular gun. It is a scientific examination because in
the process, scientific equipments are utilized by the examiner like the bullet comparison microscope,
stereoscopic microscope shadowgraph , onoscope, bullet recovery box, chronograph helixometer, taper
gage , calipher, analytical balance, and the like.
11.ORIGIN
The term “ballistics” itself was derived from the Greek word “ballo” or “ballein” which literally
means “to throw”. Its root also was said to have been derived from the name of an early Roman war
machine called the “ballista” – a gigantic bow or catapult which was then used to hurl missile or large
objects at a distance like stones against animals (games) or their enemy forces.
The meaning of the term however, has greatly broadened since the development of the “science of
firearms identification” and so today the word “Ballistics” is frequently used synonymously in the press
and in police parlance with “firearms investigation and identification. ( ex. Cross matching)
The word “forensic”, as applied to ballistics, or to any other subject, suggests a relationship to
court of justice and legal proceedings, the term was derived from the Latin word “forum”, meaning a
market place, where people gathered for “public disputation” or “ public discussion” Thus the title
“forensic Ballistics” aptly describes the subject under consideration, the science of investigation and
identification of firearms and ammunitions used in crimes.
Hence, the terms “Ballistics”, Forensic Ballistics and “Firearms Identification”, have come to mean one
and the same thing in the minds of the public.
111-BRANCHES:
The science of ballistics or firearms identification is divided into the following branches – Interior
Ballistics, Exterior Ballistics, Terminal Ballistics, and Forensic Ballistics.
Interior ( internal) Ballistics – that branch of the science which has something to do with the properties
and attributes of the projectile (bullet ) while still inside the gun. This extends from the “breech” to the
“muzzle” of the gun. This branch involves all those reactions that take place while the bullet is still inside
the gun. These include the following :
1. Firing pin hitting the primer
2. Ignition of the priming mixture
Cont of interior.
3. Combustion of the gun powder
4. Expansion of the heated gas
5. Pressure developed
6. Energy generated
7. Recoil of the gun
8. Velocity of bullet inside the barrel
9. Rotation of the bullet inside bore
10. Engraving of the cylindrical surface of barrel.
B’ Exterior Ballistics (external) – that branch of science that has something to do with the attributes and
movements of the bullet after it has left the muzzle. And this branch of science involves the following:
1. muzzle blast
2. muzzle energy
3. trajectory
4, range
a. accurate ( effective) range
b. maximum range
5. Velocity
6. Air resistance
7. Pull of gravity
8. Penetration
C. Terminal Ballistics- branch of science w/c deals w/ the effects of the impact of the projectile on the
target.
Assignment : Origin of firearms, Definition of terms, Men behind firearms, Classification, Nomenclature
and mechanics,
- Advantages of a revolver
- Disadvantages of a revolver
- Advantages of an automatic pistol
- Disadvantage of an automatic pistol
- Nomenclature and functions
- Legal and technical definition of ammunition
- Parts of cartridge
- Classification of cartridges
CHAPTER X
A- Introduction
It is necessary for the prosecutor or fiscal to be able to present his evidence in such a manner
that he can give the court a complete and clear picture of the crime and its commission.
CONT.
Physical evidence is that means by which the investigator, may bring to the attention of the
court those things on which his contention of guilt of the accused is based. It is an explanation and
presentation to the judge or court of the facts by which the officer has determined that the accused is
responsible for a criminal act.
B. RECOGNITION
It is imperative on the part of the of every police investigator to recognize properly those
physical evidences that might have come out from the use of firearm.
When collecting physical evidence, the investigator should collect all articles, which are, or may at some
future date, be of value as evidence.
a. Any physical object which may tend to show or indicate or not a crime was committed, and
Cont of 2.
b. Anything which may connect some particular person with the crime or crime scene.
d. Metal fragments
f. Holster
g. Magazine ( for automatic weapons)
h. Cartridges
i. Gloves
j. masks
4. Where possible, designate one of the officers investigating the crime to collect ALL evidences.
5. Great care should be exercised when collecting physical evidence. Be sure that you “Don’t MAC” the
evidence.
M- utilate the evidence
The investigator must take note the pertinent facts or features about the firearm/s found at the crime
scene:
Shape or form of the bullet- round nose, flat nose, pointed, etc.
Number of shells
Place of recovery
The fired bullets should be marked by the recovering officer with his “initials” on the ogive or nose or its
anterior portions, with date of recovery by stylus or any pointed instrument.
CHAPTER X1
SCIENTIFIC EQUIPMENTS GENERALLY USED IN
FIREARMS IDENTIFICATION
The following are the equipments that are generally used in a typical Ballistics Laboratory :
2. Stereoscopic Microscope
3. Shadowgraph
6. Helixometer
7. Micrometer
8. Calipher
10. Onoscope
11. Taper Gage
1. Bullet Comparison Microscope –This valuable instrument is especially designed to permit the
firearms examiner to determine the similarity and dissimilarity between two fired bullets or two fired
shells, by simultaneously observing their magnified image in a single microscopic field
3. Shadowgraph - It contains a series of microscopic lenses of different magnifications that can be used
in examining fired bullets or fired shells to determine their class characteristics and also for orientation
purposes.
4. CP – 6 Comparison Projector – A method very much similar with the bullet comparison microscope,
two fired bullets or two fired shells can be compared in one sitting of the firearm examiner.
5. Bullet Recovery Box – In test firing suspected firearms, it is standard procedure to use ammunitions
that are of the same caliber, make or brand, and manufactured in the same year as that of the evidence
bullet or shell.
The purpose of this is primarily to subject the suspected firearm to the same conditions under
which it was alleged to have used at the time of the commission of the crime.
6. Helixometer- It measure “pitch of riflings “ of firearms. Pitch of riflings is the distance advanced by the
“riflings” in one completeturn ( 360 degrees) or the distance travelled by the bullet in one complete
rotation
8. Calipher – This is an instrument used for making measurements such as bullet diameter, bore
diameter, barrel length and others of importance in firearms identification
9. Analytical or Torsion Balance – This used more or less for determining weights of bullets and shotgun
pellets – for possible determination of type, caliber, and make of firearms from which fired.
10. Onoscope - A small instrument sometimes used in examining the internal surface of the gun barrel -
in determining the irregularities inside the bore of the gun barrel. It has a tiny lamp at the terminal
portion and this is inserted inside the bore internal examinations.
- Land marks
- Groove marks
- Skid marks
- Lead bullets
- jacketed
- full metal
Interior ballistics