CHAPTER 9 Flashcards
This used to determine the similarities and dissimilarities of evidence and test evidence.
Bullet Comparison Microscope
1st to own Bullet Comparison Microscope in 1925. He is also the Father of Modern Ballistics.
Col. Calvin H. Goddard, MD
Two Positions in Comparing Evidence & Test Bullet
- Intermarriage
- Juxtaposition
half of evidence & test bullet is projected:
a. At the same time – Clock positions
b. At the same direction – Left or right
c. At the same magnification – the same size when viewed (small vs small; bigger vs bigger)
d. At the same image – landmarks vs. landmarks
e. At the same level or plane – refers to height or elevation of stage plate
Intermarriage
– the critical side by side examination of evidence and test bullet/shell. Juxtapose means putting two things together to emphasize their contrast between them.
Juxtaposition
Used in preliminary examinations of fired bullets, shells.
Used also in close-up examination of tampered serial nos. of FAs.
Stereoscopic Microscope
invented the first Stereoscopic-Style Microscope with two eyepieces in 1671.
Cherubin d’Oreans (1671
– introduced a “novel” design that led him to become the Forefather of of Modern Stereoscope.
Honorato S. Greenough (1890)
– designed the first successful stereomicroscope. This was introduced in US and was named Cycloptic in 1957.
Francis Herbert Wenham (19th) of London
Similar with the Comparison Microscope. BUT this equipment is capable of comparing two fired bullets and shells with a large screen. William Howard Livens, engineer and British Army, was the inventor.
Comparison Projector 6 (CP-6)
Used in test firing to acquire test shells and bullets for comparison. The same caliber or brand of ammunition should be used and manufactured in the same year.
Bullet Recovery Box
Original Design (Square)
1. Length = 8ft or 96 in
2. 1ft or 12 x12 in on each side
3. ¼ inc thick = side
4. 1/8 in thick = tip
Modern Design (Tube)
A. Length = 92 inches
B. Diameter of body = 18 inches
C. Thickness of iron used = 1/8 inch
D. Frontal ring = 20 inches
Used in determining the width of lands, width of grooves, diameter and twist of fired bullet.
Measuring Projector 6 (MP-6)
Generally, used to know the caliber of FA, bullet and shell.
Caliper
Caliper is used to determine the:
- Bullet diameter
- Rim diameter
- Shell mouth diameter
- Bore diameter
- Shell length
- Barrel length
Aside from use of determining the Caliber of FA, bullet, shell and ammo.
– similar in use with Caliper. The word Micrometer was derived from Greek words Micros (small) and Metron (to measure). This instrument then is used to measure small things and small distances. This is an enhancement of the Vernier Caliper. William Gascoine (17th) – first ever inventor.
Micrometer (C-clamp like)
– inventor of Palmer, which is used in measuring handheld objects. It was introduced in Spain and was called
Jean Laurent Palmer (1848-France)
Determines the weight of fired bullet, shots/pellets to know its caliber, type and make of FA used. Measurements are expressed in Grains or Grams. Note: If bullet is shaved, it must be noted for its weight will differ from the standard.
Analytical or Torsion Balance
used to determine the bore diameter of FA or Caliber.
Comparison: Ring measurer, used in determining the right measurement for wedding, graduation and personalized rings.
Taper Gauge
This is a small instrument used in the examination of the interior surface of barrel. It has tiny lamp at its end and is being inserted in the barrel to detect irregularities and imperfections, roughness and scratches.
Onoscope
This measures Pitch of Rifling, which refers to a complete turn (360°) of a bullet inside the barrel. It also measures the angle of twist of rifling, either pistol or revolver barrel.
Procedure: This instrument is used by inserting the telescope and aligning it with the axis of the bore.
Helixometer
This measures the speed the bullet or muzzle velocity of the bullet. Alfred Lee Loomis (1918) – inventor. Prior to Chronograph, Boulenge Chronograph was actually invented but was not much reliable/accurate.
Chronograph
– used in marking fired bullets, shells and FAs submitted for examination. This is being plug to a female outlet. Used only when there is power supply
Electric Gun Marker
– used in orientation/preliminary examination of fired bullets and shells with the use of series of microscopic lenses of different magnifications. This instrument contains a large circular ground glass that is about 14 in where the observation and comparison of the characteristics is done. This can also take photomicrographs
Shadowgraph
a pointed instrument used to mark:
1. fired bullets
2. fired shells
3. Firearms
4. Metallic fragments
This must be solid and harder metal than the evidence to be marked.
This is used in manually engraving the initials and date.
Stylus
Integrated Ballistics Identification System
– a mechanical trigger pull trigger tester
Trigger pull gauge
– used to handle bullets
Tweezers
– an optical device consisting of a rigid flexible tube with an eyepiece on one end, an objective lens on the other linked together by a relay optical system in between.
Borescope
– used to calculate the drag coefficient of the bullet. This is capable of determining the supersonic speed of bullet.
Wind funnel
– used to photograph projectile in flight. This enables to determine the speed, position of bullet and shock waves the projectile produces. Invented by an American Engineer Horod Eugene Edgerton
Stroboscope
– used primarily in the laboratory in marking metal evidence.
Electric Gun Marker
used to drill deep accurate holes
Gun drills/ Deep hole drills
