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CRIM BOARD EXAM FIREARMS IDENTIFICATION.ppt

CRIM BOARD EXAM FIREARMS IDENTIFICATION.ppt

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FIREARMS IDENTIFICATION Origin of Ballistics: The word “Ballistics” was originated from the Greek word “Ballo” or “Ballein” Ballo or Ballein means to throw and from a Roman war machine called “Ballista”. Ballista- a gigantic bow or catapult used throw missiles and large objects such as stones at a particular distance to deter animal or enemy forces. From those words the term Ballistics was derived to indicate the science of moving projectile. Earliest form of Ballistics Application Throwing of rocks by prehistoric man The bow and catapult
- the science of motion of projectile and the condition governing that motion. Science: it is a science in itself because it evolved from systematized body of knowledge, research, development, training, experience and education of those who pioneered in this field. Motion: Refers to the movement or mobility of the projectile from one point to another. Motion of Projectile will undergo “Yaw” until it is conquered by Gyroscopic action. What is Ballistics?
Motion: Refers to the movement or mobility of the projectile from one point to another. Motion of Projectile will undergo “Yaw” until it is conquered by Gyroscopic action. Yaw – the unstable motion Gyroscopic action – is the stillness of the rotating motion and attain its highest momentum for stability in flight and penetrating power. Projectile: the bullet being propelled
Kind of Motions 1. Direct 2. Rotary 3. Translation
Branches of Ballistics 1. Interior Ballistics – It is that branch of the study of science which has something to do with the properties of the projectile or bullet while still inside the barrel of the gun and this extends from the breech to the muzzle. This involves the following: a. Firing pin hitting the primer b. Ignition of the priming mixture c. Combustion of the gunpowder d. Expansion of the heated gas e. Pressure developed f. Energy generated g. Recoil of the gun h. Velocity of the bullet inside barrel i. Engraving of the cylindrical surface of the bullet
2. Exterior Ballistics – This branch of science has something to do with the movements and attributes of the bullet after it has left the muzzle of the gun, which involves the following: a. Muzzle blast – the sudden noise or sound created at muzzle point of the gun by reason of the sudden escape of the expanding gas as it comes in contact with the air in the surrounding atmosphere. b. Muzzle energy - the energy generated at muzzle point c. Trajectory – the actual curved path of the bullet during its flight from the muzzle of the gun.
a. Straight horizontal line. b. Parabola-like flight. c. Vertical drop. d. Range – the straight distance between muzzle and target. Effective range – the distance within which the shooter has control of his shots, meaning he can place his shots at a desired spot. Maximum range – the farthest distance that a bullet can be propelled from the firearm. Stages of trajectory:
e. Velocity - rate of speed of the bullet per unit of time. - A rifle has a muzzle velocity of 1,000 to 4,000 ft/sec. f. Air resistance – the power or capacity of the bullet to resist air during its flight from the muzzle of the gun. g. Pull of gravity – that is when the bullet plunge or dive itself after attaining its 14 inches of effective range. h. Penetration – the depth to which the bullet has entered its target or object hit.
At 200 yards an average military rifle projectile will penetrate about 24 inches of loam, oak and 7 inches of concrete. 3. Terminal Ballistics – This branch of science deals with the effects of the impact of the projectile on the target, and this involves the following: a. Terminal accuracy – that size of the bullet group on the target. b. Terminal energy – that energy of the projectile when it strikes the target. - the striking force or energy. c. Terminal penetration – that depth of bullet penetration on the target or object hit. d. Terminal velocity – velocity of the projectile when it strikes the target. Terminal Ballistics is the study of bullet penetration in solid and liquids. It can be subdivided into 1. Penetration Potential, which is the capacity of a bullet to penetrate various materials. 2. Wound ballistics , which is the effect the bullet has on living tissue.
Firearms Identification involves the following: 1. Field Investigation – This is the job of a police officer who responds to the crime scene. This is a routine job of a police investigator and this involves recognition, collection, marking, preservation, and transmittal of firearms identification exhibits like bullets, fired cartridge cases, cartridges, fragments, firearms and other allied matters. A. Recognition – the process of applying keen observation in search for physical evidence at the crime scene for proper identification.
B. Collection – is the process of gathering physical evidence that has been recognized. C. Marking – act of placing a distinctive mark on all specimens like firearms, fired bullets/cartridge cases and metallic fragments. Fired bullet should be marked by the recovering officer with his initial, or initial of the victim/suspect.
Where to mark: 1. Bullet : Mark on the ogive or nose with the corresponding time and date of recovery. : On the base if nose is badly damage. 2. Cartridge case/Empty shells: : Mark inside near the mouth, or : Mark outside near the mouth, or on the body
Do not mark on the following: a. Bullet : don’t mark on the bullet that contains rifling marks or striation. b. Cartridge case: never mark on the base of a fired shell. : don’t mark on the shoulder and neck on a cartridge case fired from a rifle like 5.56mm and 7.62mm. 3. Firearm: beside noting down its pertinent features, should be marked on the three main parts such as barrel, cylinder and the frame for revolver. In the case of pistol, be marked on the barrel, slide and frame or receiver.
Aside from marking, “tag” be attached bearing the following: - Type of firearm - Caliber -Serial number -Time and date of recovery -Name of victim -Name of suspect D. Preservation – shall mean the process of keeping and preserving of physical evidence for court presentation
Preservation of physical evidence: a. Should be wrapped in tissue paper or cotton and placed separately in a self sealing plastic or any similar container. b. Container must be properly labeled. c. The officer should record all steps he has taken in preserving the physical evidence for future use. E. Transmittal of physical evidence Once an officer has collected and marked all the physical evidence, he must transmit these ballistics exhibits as soon as possible to the Firearms Identification Division for examination.
The officer on case must be duly aware of the CHAIN OF POSSESSION OF PHYSICAL EVIDENCE. He must be able to state: a. Who recovered the evidence b. Who received the exhibits from him c. When was the exhibits submitted d. Date and time received e. Was a receipt issued and by whom 2. Technical Examination or Laboratory Examination: This is the job performed by a Forensic Firearms Examiner in the Laboratory. It involves a. marking of physical evidences. b. Test firing of evidence firearm to obtain test bullets and test shells for comparative purposes, c. Photomicrography under the bullet comparison microscope, preparation of comparative charts and reports regarding his findings and conclusion.
Seven Problems involve in Firearms Identification a. Given a bullet, to determine the caliber, type and possible make of firearm from which it was fired. b. Given a cartridge case, to determine the caliber, type and possible make of firearm from which it was fired. c. Given two or more bullets, to determine whether or not the bullets were fired from one and the same firearm. d. Given two or more cartridge cases, to determine whether or not the cartridge cases were fired from one and the same firearm. e. Given a bullet and a firearm, to determine whether or not the bullet was fired from the firearm.
f. Given a cartridge case and a firearm, to determine whether or not the cartridge case was fired from the firearm. g. Given a firearm, to determine its serviceability. 3. Legal Proceedings- Court trial: This is where the firearms identification reports and exhibits are presented and defended in Court.
TWO (2) GENERAL CHARACTERISTICS IN FIREARMS IDENTIFICATION 1. Class Characteristics – These are the characteristics that are determinable prior to the manufacture of a firearm. These characteristics are factory specifications as to the bore dimensions and within the control of man. These serve as a basis for identifying a certain group or class of firearm. a. Bore Diameter – the diameter in which the bore was reamed. It is the distance measured from one land to the opposite land. b. Number of lands and grooves – the number of lands and grooves inside the bore of a firearm are always the same.
c. Width of Lands – the width of land is dependent on the bore diameter, groove width and number. The lands are the remainder of the circumference after subtracting all the groove width. d. Direction of twist – The rifling inside the gun barrel may twist either to the left or right. The twist of rifling causes the bullet to rotate as it passes through the bore for the bullet to have gyroscopic stability during its flight from the muzzle to the target. e. Pitch of Rifling – it is the measurement of the twist of the lands and grooves. It refers to the distance advanced by the rifling in one complete turn.
f. Depth of Grooves – Grooves are usually a few thousand of an inch deep. It is equal to the height of the side of the land. 2. Individual Characteristics – are characteristics that are determinable after the manufacture of firearm. These are characteristics whose existence is beyond the control of man and which has random distribution.
MARKS FOUND ON FIRED BULLETS 1. Lands and Grooves Marks – These are found on the cylindrical or peripheral surface of the fired bullets and is caused by the rifling inside the gun barrel. 2. Skid Marks – are marks found on the anterior portions of the fired bullet and are caused by the forward movement of the bullet from the chamber before it initially rotates due to the rifling inside the gun barrel . 3. Stripping Marks – are generally found on bullets fired through loose fit barrels wherein the rifling is already worn out. 4. Shaving Mark – normally found on bullets fired from a revolver, cylinder of which a little bit off-center from the barrel.
MARKS FOUND ON FIRED CARTRIDGE CASES 1. Firing Pin Mark – generally found on the primer cup, which is the area of the base of the cartridge. On center fire cartridge the priming mixture is contained in the primer cup located in the center of the base. However, rim fire cartridge, priming mixture is contained along the rim. 2. Breech face markings – found mostly on the base of the cartridge case. 3. Extractor marks – mostly found on shells fired from pistols, rifles, shotguns and machine guns. These are found on the extracting grooves. 4. Ejector Marks – found on the cartridge case fired from automatic firearms. Both marks are located near the rim.
5. Shearing marks – These are secondary firing pin marks, and are found near the firing pin impression. 6. Magazine Lip mark – are found between two points on the rim on the base of the shell caused by the magazine lips during loading of the cartridge into the chamber ready for firing. 7. Chamber Marks – are markings that are found around the body of a fired cartridge case and are caused by the irregularities in the interior surface of the chamber.
Rifling – the helical grooves in the bore of a firearm barrel to impart rotary motion of the projectile. Types of Rifling: 1. STEYR TYPE = 4 lands, 4 grooves, Right hand twist Lands and Grooves of equal width (4R, G=L) -used in all earliest self-loading pistols. 2. SMITH AND WESSON TYPE = 5 lands, 5 grooves, Right hand twist, Lands and Grooves of equal width. (5R, G=L) 3. BROWNING TYPE = 6 land, 6 grooves, Right hand twist, narrow land and broader grooves. (6R, G2x) 4. COLT TYPE = 6 lands, 6 grooves, Left hand twist, narrow land and broader groove. (6L, G2x) 5. WEBLEY TYPE = 7 lands, 7 grooves, Right hand twist, narrow land and broader groove. (7R, G3x) 6. ARMY TYPE = 4 lands, 4 grooves, Right hand twist, narrow lands and broader grooves (4R, G3x)
Definition of Firearm: Legal definition: Section 877 of the Revised Administrative Code defines “Firearms” or “arms” as herein used, to include rifles, muskets, carbines, shotguns, pistols, revolvers, and all other deadly weapons from which bullets, balls, shots, shells, or other missiles may be charged by means of gunpowder or other explosives. This term also include air rifles, except those of limited range and of small caliber and which are used as toys. The barrel of any firearm shall be considered a complete firearm for all purposes hereof.
Technical definition: Firearm – is an instrument used for the propulsion of projectiles by means of the expansive force of gases coming from a burning gun powder Firearm – any weapon, by what ever name known which is designed to expel a projectile by the action pf an explosive and firearm muffler or firearm silencer or any part of such weapon.
CLASSIFICATION OF FIREARM ACCORDING TO ITS POWER PUR.TO R.A. 8294 Section 1. Unlawful manufacture, Sale, Acquisition, Disposition or possession of Firearms or Ammunition or Instruments Used or Intended to be used in the manufacture of Firearms or Ammunition. The penalty of prision correctional in its maximum period and a fine of not less than Fifteen Thousand Pesos (P15,000.00) shall be imposed upon any person who shall unlawfully manufacture, dealt in, acquire, dispose or posses any low powered firearm, such as rimfire handgun, .380 or .32 and other firearm of similar firepower, parts of firearm, ammunition, or machinery, tool or instrument used or intended to be used in the manufacture of any firearm or ammunition: Provided that no other crime was committed.
The penalty of prision mayor in its minimum period and a fine of thirty thousand pesos (P30,000.00) shall be imposed if the firearm is classified as high powered firearms which includes those with bore bigger in diameter than .38 caliber and 9mm such as .40, .41, .44, .45 and also lesser caliber firearms but considered powerful such as caliber .357 and caliber .22 center fire magnum and other firearms with firing capability of full automatic and by burst of two (2) or three (3): Provided, however that no other crime was committed by the person arrested.
THE END!!