SPECIAL CONSIDERATIONS ON BULLETS

1.Souvenir Bullet- lodged and remained in the body

2.Bullet Migration- not lodged in a place where it was previously located

Bullets Embolism- carried by circulating blood to some parts of the body

3. Tandem Bullet- two or more bullets leaving the barrel one after another

1. In a CLOSED LOCKED room;2. Death WEAPON is almost always found NEAR the

victim. (cadaveric spasm);3. MUZZLE in CONTACT with the part of the body;4. Entry ACCESSIBLE to the wounding hand;5. Usually SOLITARY;6. Compatible TRAJECTORY ;7. Personal HISTORY;8. Presence of GUNPOWDER in the hands;9. Entrance wound do not usually involve CLOTHINGS;10. FINGERPRINTS on the butt;11. Suicide NOTE; and12. No DISTURBANCE in the place of death.

GUNSHOT WOUND IS SUICIDAL

1. No point of ELECTION;2. Usually at some

DISTANCE;3. DEFENSE wounds;4. DISTURBANCE of

surroundings;5. Firearm NOT FOUND;

and6. TESTIMONY of witness.

GUNSHOT WOUND IS HOMICIDAL

1. ONE shot;2. No SPECIAL area of the

body;3. Testimony of assailant in

relation to the RELATIVE positions of both;

4. TESTIMONY of witness.

GUNSHOT WOUND IS ACCIDENTAL

1. Complete DESCRIPTION of the wound2. LOCATION

a) Part of the bodyb) Distance from the mid-linec) Distance from the heel or buttock

3. DIRECTION and LENGTH of bullet tract4. ORGANS or TISSUES INVOLVED5. LOCATION of missile if lodged;6. DIAGRAM, PHOTOGRAPH, SKETCH or

DRAWING

PHYSICIAN’S REPORT

TO ANSWER IN COURT1. Could the weapon inflict the wound?2. What Range?3. DIRECTION of the fire.4. Possibility that the wound is self inflicted.5. Signs of struggle.6. Resistance after the injury.7. Died instantaneously.8. Relative positions of the involved

1. Odor of the gas inside the barrel2. Chemical changes inside the

barrel3. Evidences that may be deduced

from the wound

LENGTH OF TIME FA HAD BEEN FIRED

Can the direction of the shot be determined from the direction from which the shot came from? Not possible

Can the firearm be identified by the sound of the discharge? Impossible. Accustomed-may be

1. Device is set up to enable it to be discharged at a long range by the victim;

2. GSW entry not a near shot because clothings are interposed between the victim and the firearm;

3. Physician failed to distinguish between near or far shot wound; and

4. Products of a near shot has been washed out of the wound.

GUNSHOT WOUND MAY NOT BE A NEAR FIRE OR MAY NOT APPEAR TO BE A NEAR FIRE

1. Location of the empty shells- driven out/inside cylindrical chamber

2. Nature of the spent bullet- copper jacketed/no such coating 3. Nature of the base of the cartridge or spent shell- no

difference/ wider diameter than that of the cylindrical body

AUTOMATIC PISTOLS VERSUS REVOLVER

1. Location and extraction of the bullet;

2. Reveal fragmentation and their location

3. Show bone involvement4. Reveal trajectory5. Show the effects of the

bullet wound

X-RAY EXAMINATIONS MAY

• Shoulder-fired• Smooth barrel• One or more round balls or

pellets

SHOTGUN

CLASSES OF SHOT• Bird shot- 0.05 to 0.15 “

diameter, from 200 to 400 shots• Buckshot- 0.24 to 0.33 “ in

diameter, fewer shots. 12 gauge- 9 shots

• Single projectile- single shot or slug

• LETHAL RANGE- an area of 35 to 40 “ in diameter at 30 to 40 yards

1. Contact or Near Contact Shot (not more than 6 in)- greater quantity of gunpowder in the cartridge, more damage due to muzzle blast, flame and gunpowder at the site of the wound;

a) perpendicular to the skin- round and when made in acute angle- oval;

b) entrance wound- burned, width increases as the muzzle-skin distance increases;

c) blackening due to smoke;d) GP tattooing is densely located;e) contusion of the tissue blackened by GP;

f) singeing of the hair (less than 6”);g) subcutaneous and deeper tissues are severely disrupted;h)blood tissues along the bullet tract shows presence of carbon monoxide; andi) Wad of its fragments together with shot may be recovered from the bullet tract

SHOTGUN WOUND OF ENTRANCE

2. Long Range Shot (more than 6 in)a) at 2-3 ‘ muzzle skin distance- single

wound of entry;b) at 3-4 ‘- wound is usually serrated or

scalloped circumference (rat hole);c) 1t 5-6 ‘ the wad tends to produce

independent injury;d) at 6’- shots begin to separate from the

conglomerate shot and at 10’- independent wound of entry (billiard ball “ricochette effect”);

e) smudging due to smoke up to 15 “;f) gunpowder tattooing may be detected up to 24 “g) in an unchoked shotgun, muzzle-target distance is:{distance between the 2 farthest shots in inches and subtract one (distance is in yards)}

SHOTGUN WOUND OF ENTRANCE

Measure the distance between the two farthest shot (pellets) in inches and subtract one , the number thus obtained will give the muzzle-target distance in yards.

The character of the wound and the degree of dispersal is influenced by the muzzle-target distance, gauge of the shotgun, degree of choke and the type of ammunition.

A close shot produces more serious injuries because the shots are concentrated on a specific target and because of greater kinetic energy of the pellets.

DETERMINATION OF THE PRESENCE OF GUNPOWDER COMPONENTS AND PRIMER COMPONENTS

Importance of determining the Gunpowder on the Skin of the Victim:

1. Determination of the distance of the gun muzzle from the victim’s body when fired: * distribution of the gun powder is more at the upper portion of the wound of entrance, due to the upward position of the gun muzzle when fired.

* presence of gunpowder at or near the wound of entrance shows that the gun muzzle when fired is not more than 24 inches * absence will not prelude near fire * less powder particles at the wound of entrance is observed in smokeless powder as compared with black powder.

2. Determining whether a person has fired a firearm

* dorsum of the hands are examined to determine the presence of gunpowder

BASIS OF THE TESTS

* two types of residues are liberated when gun is discharged - metallic residues- from the primer which is not only blown forward towards the target from the muzzle but also backward in the direction of the shooter - particles of burned , burning and unburned (propellant) – also in the same direction as the metallic residue

Procedures in Determining the Presence of Gunpowder1. Gross Examination or Examination with the Use of Hand Lens: * Fine black powder particles of varying sizes may be seen at the

region of the wound entrance,on the dorsum of the hands or at the outer surface of the wearing apparel of the victim.

* not conclusive 2. Microscopic Examination

a) Laboratory Test to Determine Firearm Residues * there is inference of contact or near distance of the gun

muzzle to the skin when there is burning,tattooing and smudging

visible through the naked eye.

* burning and then tattooing will gradually disappear as the muzzle distance increases.

* powder tattooing will gradually spread out to a greater area

until no longer detectible.

* minute particles of burning and unburned residues and primer

constituents can be detected in the laboratory.

Click icon to add full page picture * same test may also be applied on the dorsum of the hand of the person who may have fired the gun

* test is not conclusive * test may involve the determination of the presence of gunpowder residues of primer components

Tests for the Presence of Powder Residues

1. On the Skin (Dorsum of the Hand or Site of the Wound of Entrance) a) Dermal Nitrate ( Paraffin test, Diphenylamine test,Lung’s Test

or Gonzales Test – back of the fingers and of the hand up to the

region of the wrist is coated with paraffin, heated

at temp of 150 degrees fahrenheit. - when hardened and cooled off, some of the

powder particles will be extracted and embedded in

the pa- raffin cast. - cast will solidify after which it is removed

from the hand or site of wound entrance, inner aspect

of cast is treated with Lung’s reagent, and will

indicate a blue reaction of the minute particles that

may con- tain nitrate or nitrite.

Click icon to add full page picture - test is not conclusive - negative result is also non conclusive - test will also give positive result even after three days or even hand has been subjected to ordinary washing - subjection of a suspect to the test is not self-incriminatory as act is purely mechanical and does not require use of mental faculties2.On Clothings (esp Colored Ones) Walker’s Test ( C acid , H acid test) – uses glossy photographic paper

Tests for the Presence of Primer Components

1. Harrison and Gilroy Test – cloth is treated with reagents to detect the presence of a primer component - reagent sodium rhodinate yields red if

lead and and barium are present - blue- violet will appear when an additional

of 1.5 hydrochloric acid is added to the red

area if lead is present - bright pink if barium is present

2. Neutron Activation Analysis (NAA) –sample is obtained from the hands by the

use of paraffin or by washing the hand with dilute

- exposed to a radiaton from a nuclear reactor that emits neutrons. - technique is extremely sensitive and a very small amount can be detected - very expensive and is unable to detect if there is lead -test requires access to a nuclear reactor

3. Flameless Atomic Absorption Spectroscopy (FAAS) – sample of handwashing is subjected to a temp to vaporize the metallic elements of the primer residue - quick, sensitive and employs equipment within the econo- mic means of a modern size crime lab. - it can detect the presence of barium, antimony and lead

4. Use of Scanning Electron Microscope with a Linked X-ray Analyzer- adhesive material is used to remove any residue particles from the hand - analysis of the particles with X-ray analyzer will confirm their identification - method appears to be more specific but seldom used as the initial equipment is expensive and requires a longer period of time to analyze a case

FIREARM IDENTIFICATION

The following factors must be utilized in the identification of the firearm used in the commission of crime:

1. Caliber of the Weapon – firearm may be identified by its caliber - may be determined from the firearm itself,

from the shell, bullet, cartridge or from the character

of the wound entrance

2. Fingerprints – may be found in the butt of the firearm or at the trigger and

its guard - fingerprints found may distinguish homicidal or

suicidal nature of death

3. Fouling of the Barrel – pertains to the characteristic odor of the smoke inside the barrel of the firearm recently fired

4. Serial Number – for purposes of identification - may be tampered by the offender

Procedure of restoring Serial Number if Tampered

A) Cleaning – site of the number should be cleaned - all oil, dirt, grease and paint should be removed with

gasoline, xylol and acetone

B) Polishing – most important - medium to fine grade carborondum cloth should be used - area should always have the mirror-like surface

C) Etching – solution is swabbed continously until the numbers appear - may take several hours - etching solutions includes hydrochloric acic 80cc, distilled

water 60 cc, ethyl alcohol 50 cc, copper chloride 10 grams

D) Ballistics Examination – Ballistics is the study of physical forces reacting on

projectiles or missiles. - Forensic Ballistics conventi onally known

asfirearm identification. Deals with examination of

fired bullets and cartridge cases in a particular gun to the

exclus- ion of others

Ballistics May Be Subdivided into Three Separate and Distinct Area of Study

1) Interior Ballistics ( Internal Ballistics) – deals with what happened to the

cartridge and its bullet from the time the trigger of the

gun is pulled until the bullet exits from the barrel - deals with the study of

what hap- pened in the chamber and gun barrel after pulling

the trigger

2) Exterior Ballistics (External Ballistics) – deals with what happened to the

bullet or projectile from the moment it leaves the gun

barrel to the moment of impact on the target or object

- concerned with the flight of the

bullet and the influence of all factors in its flight.

3) Terminal Ballistics – effect of the bullet on the target or until it comes to rest

a) Medical Ballistics – form of terminal ballistics - person is the target - concerned with the penetration , severity,

and the appearance of the wound due to bullet or

missile

Basic Principles Involved in Firearm Identification

1) The quality of metal in the manufacture of the firearm is very much harder and resistant to deformity as compared with the quality of metal used in the manufacture of the cartridge, so that in the process of contact between the part of the gun involved and the cartridge , the surfaces condition of the part of the gun can easily be impressed on the shell or bullet.

2) For reasons known only to the manufacturer, firearms have certain physical characteristics of certain type of caliber which differentiate it from others. This includes the number of lands and grooves, the direction of the twist, width of the individual land or groove, style of the cannelure, etc., which become the basis of class characteristics in the firearm identification.

3) No two firearms can be manufactured with identical surface characteristics. Each firearm on close examination will show the differences. Marks on the different bullets or shells fired from one firearm have similar characteristics when viewed in the comparison microscope. Marks on different bullets or shells fired from different firearms will show variation in the findings. This is referredto as individual characteristics.

Instruments used in Firearm Identification

1) Comparison Microscope – consists of two compound microscopes which

allows comparison of two objects by looking

through a single eyepiece2) Bullet Recovery Box – used for the recovery of the test bullet and shell - test shell and bullet may be used for

comparison with the evidence bullet or shell3) Hand Lens4) Sharp pointed instrument for scraping I.D. marks5) Caliper6) Analytical Balance

Types of Marking on the Examination through the Comparison Microscope

2) Impression Type Mark ( Stamp Mark) – forcible application of a hard surface

against a softer one leaving an impression on the soft-

ter surface2)