PRELIMS 2 Flashcards
- It refers to the study of projectile penetration on tissues
WOUND BALLISTICS
is a form of physical trauma sustained from the discharge of arms or munitions.
- A gunshot wound, also known as GSW, ballistic trauma or bullet wound
– gun muzzle pressed against, or within an inch or two, of the body.
Contact
– 6 inches to 2 ft.
Close discharge
– over 2 ft. or 3 ft.
Distance Discharge
SPECIAL CONSIDERATIONS ON BULLETS
SOUVENIR BULLET – bullet has been lodged and has remained in the body
- BULLET MIGRATION – bullet that is not lodged in place where it was previously located
- BULLET EMBOLISM – special form of bullet migration when the bullet loses its momentum while inside the chamber of the heart or inside the big blood vessels and carried out by the circulating blood to some parts of the body where it may lodged
– bullet has been lodged and has remained in the body
SOUVENIR BULLET
– bullet that is not lodged in place where it was previously located
BULLET MIGRATION
– special form of bullet migration when the bullet loses its momentum while inside the chamber of the heart or inside the big blood vessels and carried out by the circulating blood to some parts of the body where it may lodged
BULLET EMBOLISM
- If the number of gunshot wounds of entrance and exit found in the body of the victim is even, the presumption is that no bullet is lodged in the body, but if the number of the gunshot wounds of entrance and exit is odd, the presumption is that one or more bullets might have been lodged in the body.
The “Odd and Even Rule” in Gunshot Wounds
- Deals with the attributes and properties of shots and pellets. Focused with the study of shots/pellets from smoothbore firearms like shotguns and muskets
SHOTS BALLISTICS
- It is an open wound produced by the penetration of pellets or shots within the tissues of the body. In shotgun fire, the pellets penetrate and usually lodged inside the body and a tendency for a wider dispersion of pellets at a certain distance except in contact and near contact fires.
SHOTGUN WOUND
COMPUTATIONS
mm-Cal. and Cal. to mm
Cal to mm (x 25.4) Cal.38–mm.38x25.4=9.652or9mm
mm to Caliber (x .03937)
5.56 mm – Cal 5.56 x .03937 = .2188972 or .22 Caliber
SYSTEM OF CALIBER MEASUREMENTS
American System (2 digits)
Expressed in hundredths of an inch such as Cal .45, .38, .25, .30.
English System (3 digits)
Expressed in thousandths of an inch such as Cal .357, .380, .223.
Continental/ European System
Expressed in millimeters such as Cal 9mm, 5.56mm, 7.62mm.
-(2 digits)
Expressed in hundredths of an inch such as Cal .45, .38, .25, .30
American System
-(3 digits)
Expressed in thousandths of an inch such as Cal .357, .380, .223.
English System
Expressed in millimeters such as Cal 9mm, 5.56mm, 7.62mm.
Continental/ European System
The 9 Problems in Forensic Ballistics
- Given an Evidence Bullet, the FA Examiner will determine its Caliber and the FA that was used
- Given an Evidence Cartridge Case / Shell, the FA Examiner determine its Caliber and the FA that was used.
- Given Two or more Evidence Bullets, the FA Examiner determine if the evidence bullets were fired from one and the same firearm, or two different firearms.
- Given Two or more Evidence Cartridge Cases /Shells, the FA Examiner determine if the evidence cartridge cases were fired from one and the same firearm or two different firearms
- Given an Evidence Bullet and an Evidence Firearm, the FA Examiner determine if the evidence bullet was fired from the evidence firearm.
- Given an Evidence Cartridge Case and an Evidence Firearm, the FA Examiner determine whether the evidence cartridge case/shell was fired from the evidence firearm.
- Given an Evidence Firearm, the FA Examiner determine if it is serviceable by test firing.
- Given an ammunition (unfired) determine its serviceability
- Given pellets/shots, determine the size of shots.
● All evidence bullets are fired bullets but not all fired bullets are evidence bullets.
● All test bullets are fired bullets.
● Test bullets are not evidence bullets but may serve as
standard specimens
● Evidence bullets maybe called slug when found in the crime
scene.
REMINDERS
Republic Act 10591
defines firearms
“refers to any handheld or portable weapon, whether a small arm or light weapon, that expels or is designed to expel a bullet, shot, slug, missile or any projectile, which is discharged by means of expansive force of gases from burning gunpowder or other form of combustion or any similar instrument or implement. For purposes of this Act, the barrel, frame or receiver is considered a firearm.
FIREARM
“are herein used includes rifles, muskets, carbines, shotguns, revolvers, pistols and all other deadly weapons from which a bullet, ball, shot, shell or other missile may discharge off by means of gunpowder or other explosives. The term also includes air rifles EXCEPT such as being of small caliber and limited range used as toys. The BARREL of any firearm shall be considered a COMPLETE FIREARM for all purposes hereof (Sec. 877, Revised Administrative Code see also Sec. 290 National Internal Revenue Code).
FIREARMS” OR “ARMS”
– An imitation firearm used in the commission of a crime shall be considered a real firearm as defined in this Act and the person who committed the crime shall be punished in accordance with this Act: Provided, That injuries caused on the occasion of the conduct of competitions, sports, games, or any recreation activities involving imitation firearms shall not be punishable under this Act. (RA 10591)
SEC. 35. Use of an Imitation Firearm.
- Is the tube, usually made of metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity.
Gun Barrel
is an instrument used for the propulsion of projectiles by means of the expansive forces of gases coming from burning gunpowder.
A firearm
is an instrument used for the propulsion of projectiles by means of the expansive forces of gases coming from burning gunpowder.
firearm
designed to be fired from the shoulder.
RIFLE
smoothbore FA designed to shoot single pellet.
MUSKET
smoothbore FA designed to shoot several pellets.
SHOTGUN
a handgun with rotating cylinder.
REVOLVER
a handgun that could be semi-auto or auto/full auto.
PISTOL
is the smallest pistol in the World, made in 1914.
Kolibri auto pistol - (Cal 2.7mm, 5 shots)
– now, considered the most powerful handgun in the world. It replaced Magnum .44.
Caliber .50
Came from the French “carabine.” This is a Cal .30 FA invented by David “Carbine” William having a barrel of not more than 22 inches as shortened versions of full-length rifles.
CARBINE
is a mechanism of FA that requires manually cocking the hammer before squeezing trigger when firing.
Single Action Firearm
is a mechanism of a FA wherein squeezing the trigger automatically releases the hammer.
Double Action Firearm
= Firearms that have no rifling (lands and grooves) inside their gun barrel.
SMOOTH BORE FIREARMS
Firearms that have rifling inside their gun barrel.
RIFLED BORE FIREARMS
–that portion of the bore remaining after the rifling of grooves have been cut
LANDS
–spiral cuts in a bore which cause the bullet to spin as it travels down the barrel
GROOVES
Refers to those type of firearms that propels projectile with more than one inch diameter.
ARTILLERY
Are firearms that propels projectile with less than one inch diameter and it can be handled, moved and operated by one man
SMALLARMS
is a type of firearm that is primarily designed for military use. Is a weapon which shoots, or is designed to shoot, automatically more than one shot without manual reloading, by a single press of the trigger.
MACHINE GUNS
Is a light, portable form of machine gun, utilizing a pistol size ammunition, having a shoulder stock that may or may not be folded and designed to be fired with both hands
SUB MACHINE GUN
● are those types of firearm that
were normally fired from the shoulder.
SHOULDER ARMS
● A shoulder weapon designed to
fire a projectile with more accuracy through a long rifled bore barrel, usually more than 22 inches.
RIFLES
These are firearms designs that were set even before the manufacture of FAs. These are the factory specifications.
CLASS CHARACTERISTICS
– determined with a bullet, shell, or bore of the gun.
Caliber or Bore Diameter
always the same in number.
No. of Lands and Grooves –
– how wide the lands and grooves. NOT always the same.
Width of Lands and Grooves
– either RIGHT or LEFT.
Twist of Rifling
– one complete turn of bullet inside the barrel.
Pitch of Rifling
– how deep the groove or the height of every land.
Depth of Grooves
refers to spiral grooves cut into the bore of a barrel which impart a stabilizing spin to the bullet.
Rifling
In case of smooth bore firearms, number of lead balls of a particular diameter it would take to equal a pound is known as gauge.
Calibre/Gauge
Whereas in case of rifled firearms, the distance between the opposite lands or grooves is known as
calibre
are indentations created when the firing pin of a firearm strikes the primer of centerfire cartridge case or the rim of a rimfire cartridge case.
Firing pin impressions
are the impression marks developed when the projectile recoils rearwards under impact of high pressure of gases produced by ignition of charge and strikes with the breech face of the firearm.
Breech Face marks
are the striation marks which are produced from the rough wallof the chamber during loading and removing of the cartridge case.
chamber marks
are the striation marks formed by the extractor of most auto-loading or repeating firearms.
Extractor marks
are the striation marks developed from giector present as an opposing edge on the rear end during ——/ removal of the cartridge case from the chamber.
Ejector marks
are determined after the manufacture of FA.
INDIVIDUAL CHARACTERISTICS
are the random marks or imperfections produced incidentally during the manufacturing of a firearm by tools and machinery.
Manufacturing Irregularities
are the irregularities in the surface of the interior of the barrel produced due to wear and tear with use, corrosion, or damage.
Striation marks
= is the type of rifling having four (4) lands and grooves, right twist and the width of the lands grooves.
(4 RG=L)
Steyer Type
= rifling having (4) lands and grooves, right twist,
the width of the grooves is two (2) times the width of the lands
(4RG2X).
Carbine Type
= rifling having (5) lands and grooves, right
hand twist , the width of the land and grooves are equal.
(5RG=L)
Smith and Wesson
= type of rifling having six (6) lands and grooves, left twist,
the width of the grooves is twice (2) the width of the lands. (6LG2X)
Colt
= type of rifling having (6) lands and grooves, right hand twist, the width of the grooves is twice the width of the lands. (6RG2X)
Browning
= Rifling having seven (7) lands and grooves, right hand twist, the width of the groove is three time larger than the boarder of the lands. (7RG3X)
Webley
= Rifling having six (6) lands and grooves, right hand twist, the width of the grooves is three time larger the width of the lands (6RG3X)
Winchester
- types of firearms designed to fire only one shot every loading.
Single shot firearms
- A type of firearms designed to fire several loads (shot) in one loading.
Repeating Arms
= Type of firearms in which reloading takes place by manipulating the bolt back and forth.
Bolt Action Type
– the breech mechanism is cycled by an external lever below the receiver
Lever action type
= types of firearms in which loading take place by back and forth manipulation of the under/over forearms of the gun.
Slide/Pump Action type
– requires a separate pull of trigger for each shot fired
Semi-automatic type
= type of firearms that constitutes a continuous firing in a single press of the trigger and while the trigger is press.
Automatic F/A
is a type of firearm that designed to shoot, automatically more than one shot without manual reloading, by a single press of the trigger.
MACHINE GUNS
- Loads, closes, fires and deloads single cartridge
SINGLE BARRELED SHOTGUN
- Side by side barrel or over and under
DOUBLE BARRELED SHOTGUN
- The operated by means of sliding lever under the barrel.
PUMP ACTION TYPE SHOTGUN/ SLIDE ACTION
- The same as auto loading rifles, the recoil action reloads the gun from the magazine.
AUTO-LOADING SHOTGUNS
- which the bore size is the same through out the barrel
CYLINDER BORE TYPE
- designed with a diminishing or reducing bore diameter type towards the muzzle
CHOKE BORED GUN
. - devices principally designed for other purpose to which a gun mechanism is incorporated also called as Freakish gun.
Cane gun, knife pistols, cellphone gun, etc
- a tool in which firearm mechanism is attached to prevent easy identification.
Freakish gun
- designed for tracing or sending signals or locating enemy troops.
Flare gun
- generally referring to all gun designed from firing tear gas.
Gas gun
- are those devices which resembles a gun designed but are generally used for construction of furniture.
Tools
- refers to gun used for trapping animals that are fired to woods
Traps
- refers to all type of homemade gun
Zip Gun
are used in hunting large fish.
Harpoon Guns
Gives direction to the bullet; the part of the gun that
initiates the path of the bullet
BARREL
– making of hole of barrel with the use of barrel
blank.
Drilling
– with the drilled hole, it is being reamed from
breech end to muzzle to remove imperfections, scratches and irregularities. This operation undergoes 1) Roughing, 2) Finishing 3) Burnishing.
Reaming
- the construction of rifling inside the barrel.
Rifling
- smoothening/polishing of the inner surface of the
barrel.
Lapping
The part of the barrel at the opposite end of the muzzle
BREECH
Also known as the bolt, it is the steel block that closes
the breech against the force of the charge during firing.
BREECHBLOCK
The part of the stock which is held against the
shoulder to stabilize the gun during firing
BUTT
The part of the bore into which a cartridge is placed; the
enlarged space at the breech of the barrel where the cartridge is fed
CHAMBER
The part of the revolver that serves as the magazine as
well as chamber for cartridges
CYLINDER
The mechanism that throws the empty shell (cartridge
case) from the firearm
EJECTOR
The mechanism that pulls the empty shell from the
chamber
EXTRACTOR
Also called receiver, the part of the gun that houses the
internal parts; the body of a firearm to which the barrel, stock, pistol grip, sights, etc. are fixed and within which lies the firing and breech mechanism
FRAME
The smaller part of the stock behind the trigger guard (for
rifles and shotguns); the part of the gun firmly held by the shooter thus stabilizing the aim while squeezing the trigger
GRIP
The part of the firing mechanism in revolvers and some
pistol that is released by the sear or the main spring once the trigger is pressed; it strikes the firing pin causing the pin to move forward and hit the primer
HAMMER
A device for storing cartridges in a repeating firearm for
loading into the chamber
MAGAZINE
The end of the front end of the barrel where the bullet or
pellet exits
MUZZLE
The fixed sight on top of the barrel near the muzzle used
to aim the gun at the target
FRONT SIGHT
The sight found at the top of the breech area; this sight
can be moved to change where the bullet will hit
REAR SIGHT
The spring in automatic or self loading weapons which
returns the bolt or breech block after recoil; sometimes known as the——-
RECOIL SPRING
return spring
The part of the gun that initiates the action when the
shooter is ready to fire his weapon
TRIGGER
The safety device designed to protect the trigger from
accidental bumping or pressing that may result to accidental firing
TRIGGER GUARD
