T18.

Topic Presentation1

CRIME SCENE PROCEDURE / FIELD INVESTIGATION

1. The crime scene

No two crime scenes are the same. The nature of the crime and agency protocols determine how the
scene is processed.

The first priority on arrival at a crime scene is to protect life. There are many circumstances in which
safety is an issue at a crime scene. Examples include booby traps, risk of fire or explosion from unsafe
apparatus at clandestine drug laboratories, exposure to biological hazards, and physical and
environmental hazards, including weather.

Steps: Upon receiving a call, the officer should always take along a loose-leaf notebook and pen to make
notes at the time and on the place and not trust his memory to reconstruct the situation for his future
convenience.

When the officer is summoned on such errand, his procedure should follow a logical pattern. His
observations should be put in writing at the time of his investigation for future reference and to produce in
court if necessary.

1. Note accurately in writing the time the call was received and by whom it was sent.
2. Note accurately the time of arrival at the scene and the correct address.
3. The investigator should ascertain if the victim is dead and if not, summon medical aid or bring the
victim to the hospital. Otherwise the body should not be disturbed.
4. Immediately clear the premises of all by-standers and under no circumstances allow anyone to
touch or remove anything in the vicinity.
5. Use every effort and means to identify the deceased
6. Take the names and addresses of all witnesses and take written notes on the statements of as many
persons as possible.
7. Measure the exact distance of the body in relation to the previously mentioned fixtures of the
premises.
8. Examine the ceiling, floors, and furniture for bullet holes, blood stains, fired bullets, fired shells or
shotgun wadding.
9. If there is a firearm at the scene, he should note in writing the following observations:
10. Exactly where fo
11. Type of weapon, caliber or gauge designation
12. Note the serial number; mark his initials on the butt or frame of the weapon for future identification.
13. Note other distinctive features.
14. Note down where the empty shells, bullets and/or firearms were found and make a diagram to
illustrate the same to show their relative distances from the body of the victim and take a
photograph of it.
15. Mark the found evidences for future identification, use your initials and state the date and place
where recovered.
16. After marking the evidence, wrap them separately and individually with soft tissue paper and note
down on the wrapper where each item was found indicating the date and time.
17. Transport the recovered evidences to the crime laboratory for examination.

NOTE:
 • When an empty shell is found at the scene of the crime, the presumption is that a semi-automatic
pistol, or automatic weapon was used.
• When no empty shell is found, the presumption is that a revolver was used.
• In the bore of a barrel, the depressed portions are the grooves and the raised portions are the lands.
• On a fired bullet, it is the reverse, the landmarks are the depressed portions, and the groove marks
are the raised portions.
• To determine the real direction of the rifling twist in a rifled barrel, peep thru the barrel, place a land
or groove on the top and look away from you. If the land or the groove inclines to the right, then it
has a right twist, and if it inclines to the left it is a left twist.
• To determine the twist of rifling from a fired bullet, look on the bullet in an elongated position. If the
lands and grooves incline to the right it is a right twist, if it incline to the left it is a left twist.
• It is the rifling of a bore that marks a fired bullet.
• A fired bullet will acquire the class characteristics of the bore of the barrel from which it was fired.
• So, if a fatal bullet will have the same class characteristics as the bore of the suspected firearm, then
it is possible that the bullet could have been fired from the suspected gun.
• To determine definitely if the bullet above was fired or not from the suspected gun, then the case
must be sent to a forensic ballistics expert who will conduct the proper examination.
• If two bullets do not have the same class characteristics, definitely and conclusively the bullets were
not fired from the same barrel.

Protecting the Crime Scene - The crime scene must be protected to minimize the risk of contamination and
loss of evidence.

Access to a scene should be limited to those with a need to be present. An officer with the power to
control access must be placed in charge of the scene. The perimeter must be secured, and a log must be
kept of persons allowed entry.

Some scenes require the participation of specialist personnel, such as a medical examiner or crime
laboratory analyst. Such personnel should be aware of the basic principles of crime scene investigation. The
officer in charge of the scene should make certain that specialist personnel adhere to processing protocol
and maintain the integrity of the crime scene.

Appropriate personal protection equipment must be worn for the safety of the wearer and to prevent
contamination of the scene.

Recording the Crime Scene - The crime scene may be documented using the following:

• Notes (Written or Audio)

• Sketches and/or diagrams
• Photography
• Video

Records should document activities taking place during the examination and processing of the scene. The
area in which the crime occurred as well as the surrounding area should be identified and documented.

2. Recognition/location of evidence

It is the process of applying keen observation in search for physical evidence at the crime scene for proper
identification.
 It is imperative on the part of every SOCO personnel and field investigators to recognize properly those
physical evidence that might come out from the use of firearms. At the scene of the crime, the SOCO
personnel or investigator must exercise alertness and extreme care in the search of physical evidence.

3. Collection of physical evidence

This is the process of gathering physical evidence at the crime scene. Photograph and sketch the physical
evidence before collecting them from the crime scene and maintain records as to when, where, who, what
and how the evidence were recovered. Great care should be exercise when collecting physical evidence.
Be sure not to MAC (mutilate, alter, contaminate) the very nature of the evidence.

Specimen subject for Processing/Recovery from the Crime Scene:

1. Firearms
2. Ammunition
3. Ammunition Components, such as:
4. Bullet
5. cartridge cases
6. pellet
7. propellant
8. wads
9. bullet fragment
10. other related specimen

Note: Always Establish CHAIN OF CUSTODY

The chain of custody for all items collected from the scene must include:

• unique identifier,
• item description,
• identity of the person who collected the item,
• time and date of collection,
• location where item was found.

4. Marking of physical evidence

This is the process of placing distinctive marks on all recovered or submitted evidence. Marking of physical
evidence is very important on the part of the firearms examiner and investigating officer, so that they can
readily identify these evidences during trial of the case in court. If these physical evidences cannot be
readily identified during trial, they become “inutile”, thus serve no evidentiary value at all. Ballistics exhibits
should be marked by means of a stylus or any pointed metal by the recovering officer with his initial or the
initial of the victim/suspect including the time and date of recovery. As a general rule, never use universal
markings such as “X” or any common marks which may lead to confusion.

5. Preservation of physical evidence

The process of keeping and preserving physical evidence for court presentation. Physical evidence like
firearms, fired bullets, fired cartridge case, pellets/shots, wads, and bullet fragments should be properly
preserved for proper presentation during the trial of the case.
6. Transmittal of physical evidence

Once the officer has marked and preserved those pieces of evidence, these pieces of evidence should be
endorsed to the PNP Crime Laboratory specifically at the Firearms Identification Division/Section for
examination.

7. Receipt of evidence

Based on laboratory protocol, evidence is typically delivered to evidence reception personnel rather
than directly to an examiner. The evidence reception personnel should provide a receipt for each
submission as documentation for laboratory and agency records. Personnel receiving evidence should
immediately inventory and document the contents of the submission, reporting any discrepancies.
 T18. Topic Presentation2

FIREARM FORENSICS

FIREARM FORENSICS

When a firearm is found at the crime scene or in the possession of a person of interest, the police officer/s
should observe gun safety when recovering and handling such article of evidentiary value. Take note that
safety is an issue that every handler of firearms must reckon.

Safety refers to the state of mind or action intended to reduce the risk of personal harm. However, it can be
also used to describe the mechanical device on a firearm intended to lock the firing mechanism thus
hinder discharge of a cartridge.

A. BASIC GUN SAFETY RULES

Gun safety is a collection of rules and recommendations that can be applied when handling firearms. The
purpose of gun safety is to eliminate or minimize the risks of unintentional death, injury or damage caused
by improper handling of firearms.

Gun safety training aims to inculcate a mindset and a set of appropriate rules. Gun users/owners must bear
in mind that firearms are inherently dangerous. Gun handlers must be taught to treat firearms with extra
caution because of their destructive capabilities. Thru training, handlers are strongly discouraged from
playing with firearms since this is a common cause of fatal ‘accident’.

Safety tips regarding actual handling of firearms:

• Do not carry a single action revolver with a round under the hammer unless that revolver is a
modern transfer-bar type, equipped with an inertial firing pin.
• Do not carry a pistol with a round in the chamber unless the pistol has an automatic firing-pin block
and/or an inertial firing pin.
• Generally avoid carrying or storing an external hammer-type firearm with its hammer cocked.
Exercise extreme care in de-cocking any external hammer firearm. Accidental discharge happens
if your thumb slips off the hammer.
• Generally avoid unloading a firearm by working the cartridges through the action one-at-a-time;
drop the magazine and then eject the round which may be left in the chamber, instead, if possible.
• Avoid trying to catch a live round (while unloading a semiautomatic pistol) by cupping your hand
around the ejection port while retracting the slide; doing so may result in an accidental discharge.

* For police officers: Remember that a backup firearm can be highly valuable to you in case your primary
firearm is inoperable or is taken from you by an assailant.

B. SAFETY MECHANISM OF FIREARMS

A safety (safety catch or lever) in firearms is a mechanism used to help prevent the accidental discharge of
a firearm, helping to ensure safer handling.

Generally, there are two types of safety mechanism:

 1. Internal safety (which typically do not receive input from the user)
2. External safety (which typically allow the user to give input, for example, toggling a lever from ‘on’ to
‘off’ or something similar).

Sometimes these are called ‘passive’ and "active’ safeties (or ‘automatic’ and ‘manual’), respectively.

Revolvers can be designed with intrinsic safety features. Three common safety mechanism found in
revolvers are: grip safety, drop safety (transfer bar safety), and hammer block safety.

Pistols have integrated safety mechanism to avoid accidental discharge or other unfortunate incidents.
Modern pistols are equipped with 2 or more of the following safety devices:

1. Thumb safety
2. Firing pin safety
3. Trigger safety
4. Sliding button safety
5. Grip safety
6. Magazine safety
7.

Important safety tips about semi-automatics:

Most semi-automatic firearms can still be loaded and will fire even after the magazine has been removed.

Although there are minorities of semi-auto pistols that have ‘magazine disconnect safety’, the vast majority
of semi-autos may have a round in the chamber which can be fired by pulling the trigger after the
magazine has been removed. In semi-automatic pistols, carbines and rifles, you must remove the
magazine first, then check and clear the chamber to confirm that the gun is unloaded.

C. CLEARING A WEAPON

You may use these guidelines when learning to unload and load firearms:

• Check the firearm – apply A-P-R-O-V-E-D. (Is it unloaded and safe to handle?)
• A-P-R-O-V-E-D is actually a derivation from the ACTS and PROVE protocols practiced in the US and
Canada. (Watch "ACTS and PROVE Semi-Auto Handgun" video below.
• Have someone who is familiar with the firearm give you guidance. Don't do this on your own!
• Use deactivated or ‘dummy’ ammo - not live ammo.
• Remember to keep your finger outside the trigger guard.
• Practice! The more comfortable you are with the operation of your firearm, the safer you will handle
it.
Follow the steps below to safely load a firearm. Keep in mind that a firearm should not be loaded until you
are able to safely and legally discharge it.

1. Make sure there is no ammunition in the firearm or any obstructions in the barrel. Follow A-P-R-O-V-E-
D procedure.
2. Know the location of other persons around you.
3. Determine if the firearm can be loaded with the safety on. If it can, activate the safety.
4. Make sure to use the correct cartridge(s) or shell(s) for the firearm by matching the data stamp on
the firearm with the head stamp on the ammunition.
5. Load the firearm. How you do this will be determined by the type of firearm you are using.

As a general rule:

• Single shot firearms: place the ammunition directly in the chamber and then close the
action.
• Lever action firearms with a tubular magazine: make sure the action is closed, load the
magazine, and then cycle the action to bring a round from the magazine to the chamber.
• Firearms with a removable box magazine: load the magazine first and then insert it into the
firearm. Close the action to load the chamber.
• Firearms with a non-removable box magazine: load directly into the magazine and then
close the action to load the chamber.
6. If you were not able to do so before, put the safety on.

D. COLLECTING FIREARM EVIDENCE

‘Do not lift or handle suspected firearm by inserting any object at the barrel.’ The proper method is to hold
the gun at the rough part of the grip, stock and/or slide where no possible prints can be deposited.

In recovering a firearm, the procedure should be as follows:

1. Record/document immediately the location/position and condition of the gun that is found at the
crime scene.
2. Firearm safety must be observed. Do not point the gun to anyone and avoid touching the trigger or
hammer.
3. In lifting or moving the gun, hold it by the textured surface on the grip/stock/slide without destroying
or placing fingerprints on the weapon.
4. While holding the gun in the safest manner, render it safe without damaging potential evidence.
5. Submit firearm to fingerprint specialist for the recovery of possible prints and foreign chemicals or
fibers. Document and recover foreign matters and place them in individual containers.
6. Record serial number, make, model, and caliber of the weapon, and mark it in manner that does
not detract its value before packaging it for transmittal to the crime lab. Marking the firearm is
important since duplicate serial numbers are sometimes found on different guns of the same make
and type/class. Do not confuse model numbers or patent numbers with serial numbers.
7. Recovered firearm must be rendered safe before submission to the crime lab. Do not submit a
loaded gun to the lab. Unfired cartridges may be left in the magazine of a weapon provided the
magazine is removed from the gun. A firearm with a cartridge in the chamber should never be
shipped even if the weapon is not cocked or on safety.
8. Never clean the bore, chamber, or cylinder before submitting a firearm, and never attempt to fire
the gun before it is examined at the laboratory.
9. Package the weapon for transmittal to the crime lab. Place the gun in a sturdy cardboard or
wooden box, well packed, to prevent shifting during transit. Rifles or shotguns should not be taken
apart.

In collecting physical evidence at the scene of shooting incident, precautionary measures should be made
to maintain the original condition of the evidence when it was discovered.
The general rule in collection states that - Do not M-A-C the physical evidence.

M (mutilation)

A (alteration)

C (contamination)

E. COLLECTION PROCEDURE OF OTHER BALLISTIC RELATED EVIDENCE

With regard to bullets found at the crime scene, follow this collection procedure:

1. Immediately photograph the bullet in its position upon discovery.

2. Record its condition and exact location (describe and sketch) before lifting, Lift bullets with gloved
hands. Do not use metal tweezers. Non-metallic tweezers may be used provided they do not scratch
the bullet’s surface.
3. Wrap recovered bullets with soft paper and seal in separate labeled pill boxes or envelopes.
4. Submit all evidence bullets recovered to the crime lab. A conclusive identification may be possible
on only one of several bullets recovered even when they all appear to be in good condition.
5. Do not attempt to clean recovered bullets before sending them to the crime lab. Bullets recovered
from a body should be air dried and wrapped in paper. Washing may destroy trace evidence.

To collect spent shells, this procedure is suggested:

1. Immediately take photographs of each shell in its position upon discovery.

2. Before lifting, record the exact location and condition of each shell as found at the scene.
3. Fired shotgun shells may be marked either on the inside or outside of the paper/plastic portion of the
casing.
4. Wrap each cartridge with paper to prevent adding more marks to those already placed by the
firearm components. Contact with other metallic objects might damage the existing marks. Place
wrapped cartridge cases in envelopes. Label and seal container.
5. Submit all evidence cartridge cases or shotgun shells recovered to the lab. Some cases contain
more identifying detail than others.
6. If examination is required to determine if a shot shell or cartridge case was fired by a specific
weapon, submit the weapon and recovered ammunition.

In collecting gunpowder residue and shot patterns, follow this procedure:

1. Submit clothing or other material showing evidence of gunpowder residue or shot holes to the lab.
The clothing should be carefully wrapped in clean paper and folded as little as possible to prevent
dislodging powder particles. Photographs of the pattern will not suffice, as in most instances
microscopic examination and chemical tests must be conducted on the exhibits themselves.
Package each item separately.
2. For gunpowder or shot pattern tests to have significance, it is essential to obtain ammunition
identical in make, type, and age to that used at the crime scene. This duplicate ammunition is
necessary for firing in the weapon in question to determine the distance of the muzzle of the
weapon from the victim or other object at the time the questioned bullet was fired.
3. Gunshot residue is extremely fragile evidence and should be collected as soon as possible
(preferably within three hours of the discharge of firearm). Use the laboratory-supplied GSR kits and
carefully follow the directions.
4. In the case of live subjects, if more than six hours have passed or if the subject has washed his hands,
it is unlikely that meaningful results will be obtained.
5. If a body is to be sampled, whenever possible, GSR collection should be performed prior to moving
the body. If this is not possible, protect the hands with paper bags.

F. MARKING BALLISTIC RELATED EVIDENCE

The following rules should be observed in marking ballistic related evidence:

 1. Make use of a hard pointed instrument such as the inscriber (stylus) in marking metallic (or hard
plastic) surface of shells, bullets and weapons. In case of shells made of hard paper or any
absorbent material, use pen with indelible ink.
2. Use distinctive mark such as initials of victim/suspect and date of recovery. Do not use X for marking
because this is a universal mark.
3. Record the mark used and the position of the mark on the object. Record any serial number or other
distinctive marks present on the object.
4. Whenever possible, personally mark the object while taking care not to damage or alter it.
5. Always mark the container where the object is placed even if the object itself is already marked.
6. When you use tags, make corresponding entry in the tag and attach it securely to the object.

Tips in marking evidence bullets:

1. Evidence bullets should be initialed by the recovering officer on the ogive or nose with his initials and
date of recovery.
2. If there are significant marks at the nose, the alternative place to put his marks should be at the
bullet’s base.
3. In case of deformed/damaged/disfigured bullets, marks should be placed at the base.
4. Do not mark at the bearing/peripheral surface because this part contains significant rifling marks
that appear as striations.

For fired cartridge cases, they should be initialed at any of the following areas:

1. inside surface near the mouth

2. outside surface near the mouth
3. body (brass case)

The firearm examiner encounters many different marks on evidence bullets or shells presented to him. All
recognizable marks on firearms and ammunition should be immediately recorded.

Every gun legitimately made today is stamped with the ff:

1. Manufacturer’s ID
2. Model
3. Caliber
4. Serial number (the most important ID stamp of a product)

G. TRANSMITTAL OF FIREARM EVIDENCE

After firearm evidence are collected, marked, sealed, and labeled/tagged properly, these should be
transmitted to the proper authority. Collected evidence must be transmitted to the crime lab of the
investigating unit or submitted immediately to the duty officer (or duly designated officer for proper entry in
the logbook of evidence custodian.

In the latter case, the concerned IOC must make a request for the transmittal of the firearm evidence to the
Crime Lab and insure that such evidence will be returned immediately to the evidence custodian upon
completion of the laboratory examination, preparation of court exhibit, and laboratory report.

The IOC should be well versed with the ‘chain-of-custody’ procedures. It is very important to have a record
of all persons who have handled the physical evidence from the time of its recovery until its final disposition
in court. Information as to who received and accepted the evidence, date and time of receiving, and
quantity and condition of the physical evidence should be document properly.
 T18. PROCEDURE AT THE SCENE OF SHOOTING INCIDENT / FIREARM FORENSICS

FIREARM FORENSICS

• Police officer/s should observe gun safety when recovering and handling firearm evidence value.

• Take note that safety is an issue that every handler of firearms must reckon.

Two major causes of gun accidents:

1. Ignorance; and

2. Carelessness

4 Basic Rules of Gun Safety

Rule 1. Consider Every Gun is Loaded

"I thought the gun was empty". This statement is usually the reason why accidents happen.

*This should be an absolute rule!

Always assume that all guns are loaded until you have personally checked that there is no ammunition in
the chamber or cylinder nor a loaded magazine inserted.

What are the parts of the gun to be checked whether or not a gun is unloaded? How do we check?

Parts to be checked:

• Magazine
 • Action / slide

• Chamber

HOW?

Check that a gun is unloaded by first - removing the magazine, second - opening the action, and third -
inspecting the chamber.

What is the proper way of passing lor handling a gun to another person?

As a matter of etiquette, pistol must be unloaded with its slide pulled back and locked when handed over
from one person to another. Cylinder of loaded revolvers must be open.

A pistol in a safe condition (chamber empty, slide locked and open, and

magazine removed)

Rule 2. Always keep the muzzle of the gun pointed in a safe direction or never let the muzzle of a gun point
at anything you do not intend to shoot (muzzle consciousness)

*This is the primary rule of gun safety.

What do you think is meant by?

• Safe direction-

• Muzzle -

Rule 3. Keep your finger off/out the trigger unless you are ready to fire (trigger finger consciousness)

Accidental firing is more often not equipment related. It is a finger unconsciously pulling the trigger before
an intention to shoot.

If your finger is kept off the trigger, where should it be?

trigger finger outside the trigger

Rule 4. Be sure of your target and what lies beyond and around it before shooting

SAFETY FEATURES

Semi-automatic pistols incorporate several positive safety devices which, if properly employed, can
minimize the danger of accidental firing. These are the ff:

a. Trigger Guard

b. Slide Lock/THUMB Safety

c. Grip Safety (common to model 1911 pistols)

CRIME SCENE PROCEDURE FOR SHOOTING INCIDENT

A. RECOGNITION OF EVIDENCE
• The process of applying keen observation in search for physical evidence at the crime scene for proper
identification.

B. COLLECTION OF PHYSICAL EVIDENCE

• The process of gathering physical evidence at the crime scene. Photograph and sketch the physical
evidence before collecting them from the crime scene and maintain records as to when, where, who, what
and how the evidence were recovered.

Great care should be exercise when collecting physical evidence.

Be sure not to MAC the very nature of the evidence.

"MAC"

M - Mutilate

A - Alter/Adulterate

C - Contaminate

Specimens subjected for Processing/Recovery from the Crime Scene:

a. Firearms
b. Ammunition
c. Ammunition Components, such as:
• Bullet
• Pellet
• cartridge cases
• primer
• propellant
• wads
• bullet fragment
• other related specimen

FIREARMS EVIDENCE COLLECTION

A. Firearms

Rules:

⁃ Make sure it is unloaded

⁃ DO NOT put a pencil into a barrel

⁃ Hold the gun at the rough part of the grip, stock and/or slide where no possible prints can be deposited.

⁃ Place ID tag on trigger guard

B. Ammunition
• Scribe on base or nose
• Package in pill box or envelope
• Wrap in tissue to protect
C. Clothing
• Protect and preserve any possible residue
• Air dry if wet
• Package separately in paper bags
 Note: Establish CHAIN OF CUSTODY

MARKING OF PHYSICAL EVIDENCE

Marking an evidence bullet

bullet base example: engraved marked "ABC

On the nose (if the base is badly damaged)

never on the body

d. PRESERVATION OF PHYSICAL

EVIDENCE

The process of keeping and preserving physical evidence like firearms, fired bullets, fired cartridge case,
pellets/shots, wads, and bullet fragments should be properly preserved for proper presentation during the
trial of the case.

1. FIREARM/S

Should be properly wrapped and placed in a container, box or envelope to prevent loss or tampering. The
container or envelope itself should be properly labelled by the recovering officer.

Properly packed firearm evidence

Unsafely packed evidence

2. BULLETS AND CARTRIDGE CASES

After having been marked, should be wrapped in a clean soft "tissue", paper or cotton and placed
separately in a self sealing plastic packet or any similar container.

The container should be properly marked/labelled.

Small Evidence Boxes

Evidence Bags, paper and plastic

e. TRANSMITTAL OF PHYSICAL EVIDENCE

Once the officer has marked and preserved those pieces of evidence, these pieces of evidence should be
endorsed to the PNP Crime Laboratory specifically at the Firearms Identification Division/Section for
examination.

NOTE:

• The IOC should be well versed with the 'chain-of-custody' procedures. It is very important to have a record
of all persons who have handled the physical evidence from the time of its recovery until its final disposition
in court. Information as to who received and accepted the evidence, date and time of receiving, and
quantity and condition of the physical evidence should be document properly.
Topic 19

LABORATORY EQUIPMENT/TOOL IN FIREARMS IDENTIFICATION

Learning Outcomes:

At the end of the lesson, the students should be able to:

• name the different scientific equipment used in firearms identification,

• explain the functions of each equipment or tool, and

• know how to use these scientific tools.

Lesson Proper:

1. Bullet Comparison Microscope - This valuable instrument is specially designed to permit the firearms
examiner to determine the similarity and dissimilarity between two fired bullets or two fired cartridge cases
by simultaneously observing their magnified image.

It is actually two microscope coupled together with a single or two eyepiece, so that when one looks
through this comparison eyepiece, he is seeing one half of what is under the other in other words, half of the
evidence bullet and half of the test bullet.

With this microscope, the firearm examiner can take photomicrographs of his observation and findings
under the eyepiece of the comparison microscope.

2. Stereoscopic Microscope - This is generally used in the preliminary examinations of fired bullets and fired
shells to determine the location of the extractor marks and ejector marks for orientation purposes. It can be
use also in the close-up examination of tampered serial numbers.

No photomicrograph can be taken in this equipment.

1. Vernier Caliper - Calipers are used to measure the distance between two opposing sides of an object. It
may be an inner dimension (such as the diameter of a hole) or an external diameter (such as the thickness
of an object). This determines the bullet diameter and barrel length.

2. Analytical Balance - More or less determines the weights of the bullets, shots and pellets for possible type,
caliber and make of firearm from which they were fired.

3. Taper Gauge - Used for determining the bore diameter of firearms.

4. Chronograph - For determining the speed of the bullet or the muzzle velocity of the bullet.

5. CP-6 Comparison Projector - This is similar to the comparison microscope. Two fired bullets or shells can be
compared in one setting. A magnified image appears on a large screen and can be observed in a
comfortable viewing distance. No mental strain because comparison of evidence is faster, easier and less
tiresome, thus allowing a more efficient and productive use of investigative time in the criminal laboratory.

6.

Electric gun marker - this equipment is used in the laboratory for marking fired bullets, fired shells and
firearms submitted for examination.

7. Measuring Projector MP-6 - Determines the width of lands, width of grooves, diameter and twist of fired
bullet.

8. Micrometer - It is a measuring tool frequently used in firearm/ toolmark examinations for measuring class
characteristics such as thickness, width, or diameter. The device consists of an outer thimble and inner
spindle joined by a fine pitch screw mechanism. On older analog or mechanical models, measurements
are read with a vernier scale or a mechanical digital readout.
The modern micrometer has an electronic display that has nearly replaced the older versions.

10. Onoscope - Used for examining the interior surface of the gun barrel.

12. Helixometer - Used for measuring the pitch of rifling.

13. Bullet Recovery Equipment - Obtaining test standards of fired ammunition components (bullets and
cartridge cases) as a basis for comparison with the class and individual characteristics of evidence items is
the first step in the identification process. Fired cartridge case collection is relatively simple.

However, fired bullet samples must be collected using techniques that decelerate and securely capture the
fired bullets within a short distance. The overarching requirement is that this be performed without damage
to the microscopic detail on the surface of the fired bullets.

• Cotton Box

• Modern Steel Cotton Box

• Water Recovery Tank

• SnailTrap Forensic Buddy - rubber ball recovery system

Over the years, several alternative techniques have been used for the recovery of fired bullets, including:

• Wet telephone books

• Oil or water-soaked sawdust

• Ballistic gelatin

• Plastic milk jugs

• Blocks of ice

COMPUTER-BASED TECHNOLOGIES

In recent years, advanced computer-based tools have been used to screen firearms-related evidence
items for potential linkages to local, regional, and international incidents. Advanced computer and optical
hardware are combined with software to manage a combination of specialized computer algorithms,
pattern recognition technology, and digital imaging.

The product of this advanced technology is a preliminary computer-based selection of high-probability

associations. As a result, investigative resources are focused on a typically smaller group of repeat offenders
who often commit a disproportionately larger percentage of shooting crimes.

1. Integrated Ballistics Identification System (IBIS) - developed by Forensic Technology, Incorporated (FTI), of
Montreal. This technology can be configured according to the needs of an individual law enforcement
agency.

In the United States the use of this technology is coordinated by the National Integrated Ballistic Information
Network (NIBIN), a group governed by an executive board with three members, including one each from

1. Bureau of Alcohol, Tobacco, Firearms and Explosives,

2. Federal Bureau of Investigation,

3. State or local law enforcement agency.

This nationally interconnected, computer-assisted system facilitates the transmission of digital images of fired
bullets and cartridge cases.

system is an investigate d entressed folled by a ations forensibl

examination per laboratory protocol for presentation in court.

MatchPoint+
After images have been uploaded into IBIS, the examiner can use a MatchPoint+ workstation to perform
correlations and on-screen preliminary side-by-side comparisons of images that are stored in the centralized
IBIS database.

BulletTrax-3D - BulletTRAX-3D is the latest technological evolution from FTI (Forensic Technology, Inc.) and is
designed to address the comparison needs of the forensic firearms examiner. When paired with MatchPoint,
it allows the examiner to personally conduct preliminary correlations prior to actual microscopic
comparisons.