swifs firearms and toolmarks procedures manual v2.2 (05.29.2008) 130 pages

8/2/2019 SWIFS Firearms and Toolmarks Procedures Manual v2.2 (05.29.2008) 130 Pages

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Dallas County Institute of Forensic Sciences Firearm & Toolmark Procedures Manual, Version 2.2

Firearm and Toolmark Unit Effective Date: 5/29/2008

Dallas County Institute of Forensic Sciences

Forensic Laboratory

Firearm & Toolmark Unit

Firearm & Toolmark Procedures Manual, Version 2.2

Authorized by:

Raymond E. Cooper

Firearms Section Supervisor

Timothy J. Sliter, Ph.D.Chief, Physical Evidence

Chris Heartsill

Acting Quality Manager


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Firearm and Toolmark Unit Effective Date: 5/29/2008i

Summary of Changes from Previous Version

Previous version: Firearm Section Procedure Manual, Version 1.0

Current version: Firearm Section Procedure Manual, Version 2.0

1. Correction of various typographical and grammatical errors.2. Various non-substantive changes in wording and format to improve clarity.3. Conversion of the hardcopy manual to an electronic form.


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Firearm and Toolmark Unit Effective Date: 5/29/2008ii

Revisions & Corrections

Firearm & Toolmark Procedures Manual, Version 2.X

Effective

Date

Description Authorized

by2/28/2008 Changes Version 2.0 to Version 2.1

Revision to SOP 13. Test Firing/WaterRecovery Tank 6.11 (pg 34) to clarify the

status of test fired ammunition as evidence

R. Cooper

5/29/2008 Changes from Version 2.1 to Version 2.2

Revision of Test Firing Recovery TankSection 6 to clarify evidence handling

procedures related to test fired evidence

Revision of Test Firing Cotton WasteRecovery Box Section 6 to clarify evidence

handling procedures related to test firedevidence

Revision of Test Firing Bullet Trap Section 6to clarify evidence handling procedures related

to test fired evidence

Revision of Remote Firing Section 6 to clarifyevidence handling procedures related to test

fired evidence.

R. Cooper


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Table of Contents

1. Physical Examination and Classification of Firearms. 4

2. Safe Firearms Handling.. 7

3. Pre-Firing Safety Examination 9

4. Trigger Pull Examination Spring Gauge 12

5. Trigger Pull Examination - Triggerscan System.. 15

6. Barrel and Overall Length Measurement of a Firearm... 17

7. Corroded Firearm Examination.. 19

8. Sound Suppressor Examination. 21

9. Malfunctioning Firearm Examination. 23

10. Bore Chamber Casting 27

11. Firearms Reference File.. 29

12. Ammunition Reference Collection..31

13. Test Firing Water Recovery Tank... 33

14. Test Firing Cotton Waste Recovery Box35

15. Test Firing Bullet Trap.. 37

16. Remote Firing 39

17. Downloading.. 41

18. Primed Cartridge Case / Shotshell.43

19. Caliber Determination.. 45

20. Stereo Microscope Measuring Eyepiece... 47

21. GRC Utilization..50


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Table of Contents (continued)

22. Wad Determination.52

23. Shot Determination 5424. Physical Examination & Classification of Fired Projectiles.. 5725. Physical Examination & Classification of Cartridges & Fired Cartridge

Cases59

26. Physical Examination & Classification of Shotshells and Fired

Shotshells61

27. Microscopic Comparison...

63

28. Trace Material Examination.. 6529. National Integrated Ballistic Information Network. 6830. Chronograph

70

31. Distance Determination Test 7232. Examination & Physical Classification Tool 7333. Trace Examination- Tool... 7534. Test Standards .. 78

35. Examination & Physical Classification Toolmark.. 8036. Trace Material Collection Toolmark. 8237. Microscopic Comparison.. 8538. Casting. 8739. Miscellaneous Cylinder Examination.. 89

40. Key Examination 9141. Lock Set Examination 93


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Table of Contents (continued)

42. Polishing. 95

43. Chemical Restoration97

44. Heat. 101

45. Electrochemical. 103

46. Fracture Match Comparisons.. 105

47. Testimony Monitoring... 107

48. Appendix 1 Range of Conclusions.. 108

49. Appendix 2 Calibration Standards.. 109

50. Appendix 3 Work Sheets.. 112


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PHYSICAL EXAMINATION and CLASSIFICATION of FIREARMS

1.0 INTRODUCTION

1.1 The initial examination of any firearm will include the completion of a firearmworksheet. This worksheet will include the manufacturers data of the

firearm and will serve as a source to document the condition of the firearmas received and any tests performed to or with the firearm.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Pre-Firing Safety Checks1.2.3 Trigger Pull Examination1.2.4 Barrel and Overall Length Measurements

2.0 SAFETY CONSIDERATIONS

2.1 This procedure involves hazardous materials, operations and equipment.This procedure does not purport to address all of the safety problemsassociated with its use. It is the responsibility of the individual examiner topractice the appropriate safety and health practices. Proper caution mustbe exercised and the use of personal protective equipment must beconsidered.

2.2 Appropriate hearing and eye protection must be worn when applicable.

3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE

5.0 MINIMUM ANALYTICAL STANDARDS and CONTROLS

5.1 NONE


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6.0 PROCEDURE or ANALYSIS

6.1 A firearm worksheet should be filled out. The worksheets are dynamicdocuments and may change as the need arises. However, the worksheetwill include noting the following: (if applicable)

6.26.2.1 Laboratory Case Number6.2.2 Dallas Police Department Gun Tag Number6.2.3 Item Number6.2.4 Type of Firearm6.2.5 If the firearm was received loaded6.2.6 Make6.2.7 Model6.2.8 Caliber/Gauge6.2.9 Serial Number6.2.10 General Rifling Characteristics

6.2.10.1 Number of Lands and Grooves6.2.10.2 Direction of Twist

6.2.11 Barrel Length6.2.12 Location of Examiners Markings6.2.13 Residue in Bore6.2.14 Residue in Cylinder (Revolvers)6.2.15 Cylinder Flare (Revolvers)6.2.16 Number of Flares (Revolvers)6.2.17 Description of Firearm Finish6.2.18 Choke (Shotguns)6.2.19 Action Type6.2.20 Safeties

6.2.21 Trigger Pull Single Action and Double Action6.2.22 Magazine or Cylinder Capacity6.2.23 Push-Off6.2.24 If ammunition was furnished with firearm6.2.25 Test Fire Information

6.2.25.1 Number of test fires6.2.25.2 Where test fired6.2.25.3 Ammunition used to test fire from evidence or laboratory6.2.25.4 Brand of ammunition used to test fire6.2.25.5 If test fired components were retained6.2.25.6 General ejection direction

6.2.25.7 Operating Condition6.2.25.8 Breech Face Marks Description6.2.25.9 Firing Pin Impression Description6.2.25.10 Microscopic Description of Firing Pin Impression6.2.25.11 Firing Pin Drag

6.2.26 Entry into NIBIN6.2.27 Results of Examination


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6.3 At the discretion of the examiner observations can include the following:

6.3.1 Any other information the examiner might find useful

7.0 APPROPRIATE APPENDICES

7.1 Appendix 3 - Work Sheets


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SAFE FIREARM HANDLING

1.0 INTRODUCTION

1.1 Firearms evidence in the laboratory environment is not dangerous if

handled correctly, cautiously and safety. Occasionally, loaded firearms arereceived in evidence for a particular examination. These, of course, needvery special handling. All firearms must be treated as though they areloaded. This rule cannot be over stressed and must be followed at alltimes, whether its in the evidence receiving area, firearms section, testfiring area or in court. Safe firearm handling within the laboratoryenvironment corresponds with safe firearm handling in general. The onlyway to prevent accidents is to practice safety at all times.

1.2 OTHER RELATED PROCEDURES1.2.1 Physical Examination and Classification of Firearms

1.2.2 Pre-Firing Safety Checks1.2.3 Trigger Pull Examination1.2.4 Barrel and Overall Length Measurements


2.1 This procedure involves hazardous materials, operations and equipment.This procedure does not purport to address all of the safety problemsassociated with its use. It is the responsibility of the individual examiner topractice the appropriate safety and health practices. Proper caution mustbe exercised and the use of personal protective equipment must be

considered.


3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


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5.1 NONE


6.1 The muzzle of the firearm must always be pointed in a safe direction.

6.2 Prior to any examination, regardless of which section is receiving thefirearm, a competent individual must ascertain the loaded or unloadedcondition of the firearm.

6.3 Test firing or any examination of the firearm where ammunition is loadedinto a firearm, will only be performed in designated test firing areas.

6.4 A firearm will not be placed in the evidence vault or returned to any agencyin a loaded condition.


7.1 NONE


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PRE-FIRING SAFETY EXAMINATION

1.0 INTRODUCTION

1.1 It is the responsibility of the firearm examiner to ensure that all appropriate

safety function checks are performed on a firearm or item of ammunitionprior to test firing. The following is a list of safety checks that should beconsidered. The examiner must be mindful that individual case situationsmay require a more extensive function test process than that which is listedhere.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling




3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


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6.1 Deciding Whether Or Not A Firearm Can Be Safely Test Fired From TheNormal Hand Held Position.

6.1.1 Is the chamber/bore clear?

6.1.2 Are there any signs of cracks or weaknesses in major parts of thefirearm; such as the frame, slide or barrel?

6.1.3 Does the firearm function, lock-up or dry fire as you would expect itto?

6.1.4 Is the correct ammunition being utilized?

6.2 Is it Appropriate To Utilize The Evidence Ammunition?

6.2.1 Are there signs of reloading? If so, reconsider the need to test firethe evidence ammunition.

6.2.2 Are there splits in the cartridge case neck and/or other significantdamage to the cartridge case?

6.2.3 Is the ammunition of the correct caliber? This assessment of calibercannot be based on the head stamp!

6.2.4 Are there existing toolmarks on pertinent surfaces of theammunition?

6.2.5 Is the ammunition needed for other tests; i.e., range determinations?

6.3 Muzzle Loaders.

6.3.1 Does the chamber/barrel appear sound?

6.3.2 Do the percussion nipples have oversize flash holes?

6.3.3 If a black powder firearm is received in the loaded condition, it shouldbe rendered safe as soon as possible.


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6.4 INTERPRETATION OF RESULTS:

6.4.1 If any of the above considerations cannot be answered with a clear"yes" or otherwise rectified and test firing is necessary, that firearmmust be remote fired.


7.1 Appendix 3 Work Sheets


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TRIGGER PULL EXAMINATION SPRING GAUGE

1.0 INTRODUCTION

1.1 One of the routine examinations conducted in a firearms identification

examination is determining the trigger pull of a firearm. Trigger pull isdefined as the amount of force which must be applied to the trigger of afirearm to cause sear release. This examination can provide vitalinformation regarding the mechanical operating condition of the firearm.The trigger pull of a firearm can be obtained utilizing a spring gauge whichmakes contact with the trigger at a point where the trigger finger wouldnormally rest.

1.2 OTHER RELATED PROCEDURES1.2.1 Physical Examination & Classification of Firearms1.2.2 Safe Firearm Handling

1.2.3 Trigger Pull Examination TriggerScanTM

System




3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 Spring Gauge


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5.1 NONE


6.1 There is a remote possibility that the firearm may be damaged during thisexamination.

6.2 SINGLE ACTION TRIGGER PULL

6.2.1 Insure that the firearm is unloaded

6.2.2 Cock the firearm

6.2.3 Hold the firearm where the muzzle is parallel to the spring gauge.

6.2.4 Insure the Spring Gauge indicator is zeroed

6.2.5 Rest the trigger hook of the Spring Gauge on the trigger where thetrigger finger would normally rest. Make sure it is not touching anyother part of the firearm and the Spring Gauge is parallel to the boreof the firearm.

6.2.6 Apply pressure to the Spring Gauge, until the sear releases

6.2.7 Check two or three times, resetting the sear connection after eachattempt

6.2.8 Record the lightest and heaviest weights necessary for sear release

6.2.9 It should be noted that measuring the trigger pull of a rimfire firearmmust not be performed on an empty chamber. A dummy cartridgemust be used. The examiner must also take into consideration thepotential for damage of a centerfire firearm and may wish to use adummy cartridge in this instance as well.


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6.3 DOUBLE ACTION TRIGGER PULL

6.3.1 Insure that the firearm is unloaded.

6.3.2 Hold the firearm where the muzzle is parallel to the spring gauge.

6.3.3 Insure the Spring Gauge indicator is zeroed.

6.3.4 Rest the trigger hook of the Spring Gauge on the trigger where thetrigger finger would normally rest. Make sure it is not touching anyother part of the firearm and the Spring Gauge is parallel to the boreof the firearm.

6.3.5 Apply pressure to the Spring Gauge, until the sear releases.

6.3.6 Check two or three times, resetting the sear connection after eachattempt.

6.3.7 Record the lightest and heaviest weights necessary for sear release.


6.4 INTERPRETATION OF RESULTS

6.4.1 The results acquired are only an approximation and a different

technique may lead to a different trigger pull weight. The trigger pullis normally recorded to the nearest weight increment.


7.1 Appendix 2 Calibration Standards



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TRIGGER PULL EXAMINATION TriggerScanTM System

1.0 INTRODUCTION

1.1 One of the routine examinations conducted in a firearms identificationexamination is determining the trigger pull of a firearm. Trigger pull is

defined as the amount of force which must be applied to the trigger of afirearm to cause sear release. This examination can provide vitalinformation regarding the mechanical operating condition of the firearm.The trigger pull of a firearm can be obtained utilizing a computerizedTriggerScanTM system.

1.2 OTHER RELATED PROCEDURES1.2.1 Physical Examination & Classification of Firearms1.2.2 Safe Firearm Handling1.2.3 Trigger Pull Examination Spring Gauge




3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 TriggerScanTM System


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5.1 NONE


6.1 The TriggerScanTM System Procedures manual should be followed in orderto measure the trigger pull force using this system.

6.1.1 Check two or three times, resetting the sear connection after eachattempt.


6.2 INTERPRETATION OF RESULTS

6.2.1 The results acquired are only an approximation and a differenttechnique may lead to a different trigger pull weight. The triggerpull is recorded to the nearest weight increment measured inpounds.





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BARREL and OVERALL LENGTH MEASUREMENT of a FIREARM

1.0 INTRODUCTION

1.1 One of the routine procedures conducted in a firearms identificationexamination is determining the barrel length and in some cases the overall

length of a firearm. Barrel length is defined as the distance between theend of the barrel and the face of the closed breechblock or bolt for firearmsother than revolvers. On revolvers, it is the overall length of the barrelincluding the threaded portion within the frame. Barrel length normallyshould include compensators, flash suppressor, etc., if permanently affixed.Overall length of a firearm is defined as the dimension measured parallel tothe axis of the bore from muzzle to a line at right angles to the axis andtangent at the rearmost point of the butt plate or grip. Removable barrelextensions, poly chokes, flash suppressors, etc., are not part of themeasured barrel length or overall length.

1.2 OTHER RELATED PROCEDURES1.2.1 Physical Examination & Classification of Firearms




3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 Ruler (and/or)4.2 Tape Measurer (and/or)4.3 Non-marring Dowel


5.1 NONE



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6.1 Care must be taken if any object is placed down the barrel to help expeditethe measurement. Only a non-marring item may be placed down the barrel.

6.2 BARREL LENGTH:

6.2.1 REVOLVERS:

6.2.1.1 Measure the distance from the muzzle to the breech end ofthe barrel, excluding the cylinder. This measurement canbe done directly or by placing a non-marring item down thebarrel, marking the distance from the muzzle to the breechend of the barrel and measuring this item.

6.2.1.2 This measurement will be recorded in inches.

6.2.2 FIREARMS OTHER THAN REVOLVERS:

6.2.2.1 Measure the distance from the muzzle to the breech facein a closed and locked position. This measurement can bedone directly or by placing a non-marring item down thebarrel, marking the distance from the muzzle to the breechend of the barrel and measuring this item.

6.2.2.2 This measurement will be recorded in inches.

6.3 OVERALL LENGTH:

6.3.1 Measure the distance from the butt to the muzzle. Measurementshall be made parallel to the bore and record in inches.


6.4.1 Measurements obtained should be considered approximations giventhe accuracy limitations of most measuring devices.





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CORRODED FIREARM EXAMINATION

1.0 INTRODUCTION

1.1 Corroded firearms or those found in water, etc. may be submitted for

examination. Immediate attention must be given to these firearms toprevent further damage to the firearm. The examiner should instruct anagency recovering the firearm in a fluid such as water, to submit the firearmin a container of the fluid. If this is not practical, the firearm can be sprayedwith a product that displaces water. It should be noted that the firearmmight be too rusted to be functional. It is the examiners discretion to testfire a firearm based on its condition. The firearm will be test fired only if theexaminer determines it is safe to do so.


1.2.2 Physical Examination & Classification of Firearms




2.3 Any firearm that cannot be unloaded must be examined in an areadesignated for firing firearms (preferably a range).

3.0 PREPARATION

3.1 NONE


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4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


6.1 Determine if the firearm is loaded and if it is, unload the firearm. If it cannot be readily verified to be unloaded it must be examined in an areadesignated for the firing of firearms.

6.2 An examiner must take all necessary steps to insure that the firearm isunloaded. This may include the necessity of cutting the firearm apart.

6.3 The examiner must determine to what extent restoring the firearm isnecessary (i.e., for test firing, for recovering manufacturer information, serialnumber, etc.).

6.4 Soak the firearm in penetrating oil, de-rusting solvents or similar material.

6.5 Periodically check the firearm until the firearm functions, or the desiredinformation is recovered.

6.6 Clean the firearm with gun cleaning solvent and cleaning patches. Caremust be taken if any object is placed down the barrel that may impart marksto the interior surface.




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SOUND SUPPRESSOR EXAMINATION

1.0 INTRODUCTION

1.1 A sound suppressor is any device attached to the barrel of a firearmdesigned to reduce the noise of discharge. Sound suppressors can be

commercially produced or homemade. They are typically tubular metaldevices, but may vary in shape or form.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Physical Examination & Classification of Firearms


2.1 This procedure involves hazardous materials, operations and equipment.This procedure does not purport to address all of the safety problems

associated with its use. It is the responsibility of the individual examiner topractice the appropriate safety and health practices. Proper caution mustbe exercised and the use of personal protective equipment must beconsidered.


3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


6.1 Examine device to determine if it is, or is characteristic of, a soundsuppressor device.


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6.2 Examiner will document and record his/her findings. After an initialexamination, a report can be issued that the device is, or is characteristic of,a sound suppression device.

6.3 Testing of a firearm and firearm/sound suppressor combination must beconducted in an appropriate setting, usually a range.

6.4 The examiner should test-fire the firearm with the sound suppressor affixedand with it removed to compare the sounds produced.




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MALFUNCTIONING FIREARM EXAMINATION

1.0 INTRODUCTION

1.1 A firearms examiner may be called upon to examine a firearm to determine

if it will malfunction. Many of these cases deal with the question "Will thefirearm fire without pulling the trigger?" In these examinations, it is the goalof the examiner to acquire a detailed account of the incident, thereafterthoroughly examining and testing the firearm. Examinations can includeexternal and internal observations, x-ray examinations, or striking ordropping the firearm in attempts to duplicate the incident as reported. Theexaminer should attempt to conduct his/her examinations in a manner so asnot to alter the gun. However, there may be times when damage mayoccur. Any change to the gun must be specifically documented in theexaminers notes.

1.2 OTHER RELATED PROCEDURES Safe Firearm Handling1.2.1 Primed Cases




3.0 PREPARATION

3.1 NONE


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4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


6.1 No one procedure can sufficiently outline the steps necessary to examine allfirearms for any malfunction. However, the following list of examinationsshould serve as a guideline(not mandatory) for the examiner:

6.1.1 Physical Check (Condition of Firearm as Received):6.1.1.1 Cocked/uncocked6.1.1.2 Safety position6.1.1.3 Loaded/unloaded6.1.1.4 Cartridge position6.1.1.5 Stuck cartridges/discharged cartridge cases6.1.1.6 Presence and/or location of cylinder flare(s)6.1.1.7 If the firearm is to be x-rayed, this may be the time to do it.

6.1.2 Visual Abnormalities:6.1.2.1 Barrel (loose, etc.)6.1.2.2 Receiver (condition)6.1.2.3 Slide (condition)6.1.2.4 Parts broken or missing especially: firing pin, ejector or

extractor

6.1.2.5 Screws (loose or missing)6.1.2.6 Alterations or adaptations6.1.2.7 Sights


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6.1.3 Action (External):6.1.3.1 Are the relationships of the action parts correct?6.1.3.2 Is the assembly correct?6.1.3.3 Does the action lock normally on closing?6.1.3.4 Cylinder rotation (securely locks).6.1.3.5 Hand relationship to the ratchet (worn).6.1.3.6 Trigger (not returning, sticks, broken spring, etc.)6.1.3.7 Check the trigger pull (single action, double action) and

striking of hammer.

6.1.4 Safeties:6.1.4.1 , , full cock, seating check (any false seating positions,

push off, etc.)6.1.4.2 Grip, magazine, disconnector: function6.1.4.3 Thumb/finger - note positions when firearm will fire6.1.4.4 Rebound hammer or inertia firing pin

6.1.4.4.1 Will firing pin ride on primers?6.1.4.4.2 Is firing pin frozen or bent?6.1.4.4.3 (Drop hammer several times to check above

safeties.)6.1.4.5 Does the slide or bolt have to be completely closed to fire?6.1.4.6 Can the safeties be bypassed?

6.1.4.6.1 Will dropping hammer bypass safeties? (Thismay require primed cartridge tests.)

6.1.4.6.2 Will a light blow with a non-marring tool on therear of the hammer, when it is in battery,discharge the primer?

6.1.4.6.3 Is the firing pin impression off center (both singleaction and double action operation)?

6.1.5 Action Check:6.1.5.1 Check feeding

6.1.5.1.1 magazine6.1.5.1.2 carrier or lifter6.1.5.1.3 feed ramp6.1.5.1.4 magazine lips, etc.

6.1.5.2 Will a cartridge fire on closing of the bolt or slide?6.1.5.3 Extractor and/or ejector markings on evidence

cartridges/discharged cartridge cases consistent with whatis expected?

6.1.5.4 Unusual marks exhibited on the cartridges/dischargedcartridge cases.

6.1.6 Check for any inherent "quirks" known about the particular firearmbased on literature or case data.

6.1.7 Test Fire Firearm (note operation, misfires, etc.):6.1.7.1 Note any operational problems.


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6.1.7.2 Ammunition involved (proper cartridge, type, reloads, etc.).6.1.7.3 Check consistency of the impression on test and evidence.

6.1.8 Special Situational Tests:6.1.8.1 Discretion should be considered in situational testing if the

force needed could disturb the internal action and/or causechanges which might prevent determining the exact causeof the malfunction.

6.1.9 Action (Internal)6.1.9.1 Hammer notch(s)

6.1.9.1.1 Worn6.1.9.1.2 Burrs6.1.9.1.3 Dirt, etc.

6.1.9.2 Sear6.1.9.2.1 Worn6.1.9.2.2 Broken6.1.9.2.3 Burrs, etc

6.1.9.3 Safeties (relationships and general parts relationship).6.1.9.4 Springs

6.1.9.4.1 Weak6.1.9.4.2 Broken6.1.9.4.3 Altered, etc

6.1.9.5 Signs of any tampering or faulty assembly.




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BORE CHAMBER CASTING

1.0 INTRODUCTION

1.1 Occasionally, firearms are received for which the caliber may not be knownor may be different than is designated on the firearm and in the literature. In

order to facilitate firing of test shots that are of the correct caliber for aparticular firearm, it may be necessary to make a bore and/or chamber cast.Then, by measuring the cast, the correct cartridge can be selected for testfiring.



2.1 This procedure involves hazardous materials, operations and equipment.

This procedure does not purport to address all of the safety problemsassociated with its use. It is the responsibility of the individual examiner topractice the appropriate safety and health practices. Proper caution mustbe exercised and the use of personal protective equipment must beconsidered.


3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


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6.1 Casts can be made using various casting materials such as low meltingpoint metals and silicone rubber compounds. The procedure below is forMikrosil.

6.1.1 Insure that the firearm is unloaded

6.1.2 Open the action and remove the bolt or bolt assembly

6.1.3 Check the bore to make sure it is clear

6.1.4 Push a cleaning patch in the barrel, from muzzle end, until it is inch to inch from the beginning of the chamber

6.1.5 Lubricate the chamber with gun oil, silicone spray or some othersimilar substance such as WD-40

6.1.6 Mix Mikrosil as per manufacture instructions and carefully pourinto the chamber until full

6.1.7 Do not allow casting material to flow into breech. It will makeextraction difficult.

6.1.8 When casting material is set or cool, depending on type used,gently tap end of cleaning rod to loosen cast from the chamber andremove from the breech.

6.1.9 Mikrosil has to be pushed/forced out and is not reusable.

Therefore, it is undesirable to let any more of the casting materialthan necessary go into the barrel.

6.1.10 The same steps may be used in the casting of the bore. Howeverin bore casting, only the last three (3) inches of the bore need to becast.

6.2 INTERPRETATION OF RESULTS:6.2.1 The correct caliber of the firearm can be determined by measuring

the mouth, base, overall length, rim (if pertinent) and shoulderlength of the cast.


7.1 NONE


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FIREARMS REFERENCE FILE

1.0 INTRODUCTION

1.1 A Firearms Reference File or Library is maintained by the laboratory for

various scientific reasons, to include:

1.1.1 To identify the make, model and source of evidence firearms.

1.1.2 To provide exemplar firearms for various scientific testing purposeswhich might otherwise compromise an evidence firearm.

1.1.3 To provide an exemplar resource for training purposes.

1.1.4 To provide a source of firearms parts for the temporary repair ofevidence firearms for test-firing purposes.

1.1.5 To provide a resource for the identification of firearms partsrecovered at a crime scene.

1.1.6 To provide a resource for the location and style of firearm serialnumbers.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Ammunition Reference File



3.0 PREPARATION

3.1 NONE


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4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


6.1 A Firearms Reference File must be controlled.

6.1.1 When a gun is donated to the Firearm Reference Library, it must beaccompanied by appropriate paperwork releasing it to the laboratory.

6.1.2 The gun is then given a Firearm Reference Number, entered into thedatabase, tagged, and stored in the Firearm Reference Library.

6.1.3 In the event that a firearm is required to be returned to the submittingagency, a release form must be generated.


7.1 NONE


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AMMUNITION REFERENCE COLLECTION

1.0 INTRODUCTION

1.1 The Ammunition Reference Collection is defined as a collection orcataloging of both cartridges and components utilized for various scientific

reasons, to include:1.1.1 To identify the manufacturers cartridge designation and source ofevidence ammunition or component parts thereof.

1.1.2 To provide an exemplar resource for training purposes.

1.1.3 To provide a resource for the identification of ammunitioncomponents recovered at a crime scene and autopsies.


1.2.2 Firearms Reference Collection



3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


6.1 When handgun and rifle ammunition is purchased for the reference file, if aspecific cartridge type is not represented in the file, one will be broken downinto its components and placed in the file. The container for the remainingammunition will then be labeled to correspond with the placement of therepresented cartridge in the reference file.


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6.1.1 The numeric code on the ammunition packaging will be in thefollowing format:

010203

The first two digits, 01,refers to the file drawer numberThe second set of digits,02, refers to the box number within thedrawer.The third set of digits, 03, refers to the quadrant within the box.

6.2 When shotgun ammunition is purchased for the reference file, if a specificshotshell type is not represented in the file, one will be broken down into itscomponents and placed in the file. The container for the remainingammunition will then be labeled to correspond with the placement of therepresented shotshell in the reference file.

6.2.1 The alphanumeric code on the ammunition packaging will be in thefollowing format:

SG14

The letters SG refers to shotgun and the numeric portion 14 refersto the placement of the specimen in the file which is organized innumeric order.


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TEST FIRING

WATER RECOVERY TANK

1.0 INTRODUCTION

1.1 In order to perform a microscopic comparison of test shots from a submittedfirearm, a suggestion of two (2) test shots should be fired and recovered.Recovery methods include the water tank and the cotton waste recoverybox. The type of firearm and ammunition tested will usually dictate the typeof recovery method used. The water recovery tank is usually used torecover bullets from handguns and rifles.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Remote Firing

1.2.3 Downloading1.2.4 Primed Cases



2.2 Appropriate hearing and eye protection must be used.

2.3 One should be aware of the maximum velocity of the projectile that can befired into a particular water tank, as well as the proper water depth neededfor firing.

3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


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6.1 When possible the examiner will mark the bullet and cartridge case of eachtest shot with:6.1.1 the laboratory case number and/or6.1.2 the item number and/or6.1.3 the examiner's markings

6.2 If direct marking of the item is not possible (eg. due to size or condition)then the packaging of the item will be labeled

6.3 Test fires will be designated as TF in the evidence numbering system; e.g.,1TF-1 and 1TF-2 would be two test fires from item 1.

6.4 The examiner should consider indexing and sequencing each shot andperform these functions if necessary.

6.5 Proper hearing and eye protection must be worn.

6.6 Ensure that the water level is appropriate.

6.7 Ensure that all lids or doors of the water recovery tank are closed.

6.8 Ensure all available warning and ventilation systems are activated.

6.9 The examiner should consider loading no more than two (2) cartridges intothe firearm during the initial testing of the firearm.

6.10 Fire the firearm through the shooting port. If the firearm is capable of firing

both single and double action modes, a minimum of one (1) shot per modemay be obtained at the examiners discretion.

6.11 Recover the bullets using the appropriate device.

6.12 Ejected cartridge cases must be retrieved.

6.13 Any recovered bullets or cartridge cases used in test firing a firearm will bereturned to the investigating agency. All test fires will be consideredevidence and will be tracked using the Physical Evidence Section Chain ofCustody form.


7.1 NONE


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TEST FIRING

COTTON WASTE RECOVERY BOX

1.0 INTRODUCTION

1.1 In order to perform a microscopic comparison of test shots from a submittedfirearm, a suggestion of two (2) test shots will be fired and recovered.Recovery methods include the water tank and the cotton waste recoverybox. The type of firearm and ammunition tested will usually dictate the typeof recovery method used. The cotton waste recovery box is usually used torecover bullets from handguns, rifles and slugs fired from shotguns.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Remote Firing1.2.3 Downloading

1.2.4 Primed Cases




2.3 One should be aware of the capabilities of the particular cotton wasterecovery box being used.

3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE



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6.6 The examiner should consider the placement of paper partitions at variouspoints in box to ensure tracking of the test shot, as well as insuring that thecotton is packed down so as not to retain previous bullet paths.

6.7 Ensure that all lids or doors of the box are closed.



6.10 Fire the firearm through the shooting port. If the firearm is capable of firingboth single and double action modes, a minimum of one (1) shot per modemay be obtained at the examiners discretion.

6.11 Bullets should be recovered by searching through cotton, using partitions asguides.


6.13 Any recovered bullets or cartridge cases used in test firing a firearm will bereturned to the investigating agency. All test fires will be considered

evidence and will be tracked using the Physical Evidence Section Chain ofCustody form.


7.1 NONE


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TEST FIRING

BULLET TRAP

1.0 INTRODUCTION

1.1 In order to perform a microscopic comparison of a submitted firearm, asuggestion of two (2) test shots should be fired and recovered. Recoverymethods include the water tank and the cotton waste recovery box. Thetype of firearm and ammunition tested will usually dictate the type ofrecovery method used. The bullet trap is usually used to test fire firearmswhen the recovery of the fired projectile(s) is not necessary.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Remote Firing1.2.3 Downloading1.2.4 Primed Cases


2.1 This procedure involves hazardous materials, operations and equipment.This procedure does not purport to address all of the safety problemsassociated with its use. It is the responsibility of the individual examiner topractice the appropriate safety and health practices. Proper caution must

be exercised and the use of personal protective equipment must beconsidered.


2.3 One should be aware of the capabilities of the particular bullet trap beingused.

3.0 PREPARATION

3.1 NONE


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4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE









6.8 Fire the firearm into the front of the trap. If the firearm is capable of firingboth single and double action modes, a minimum of one (1) shot per modemay be obtained at the examiners discretion.


6.10 Any recovered bullets or cartridge cases used in test firing a firearm will bereturned to the investigating agency. All test fires will be considered

evidence and will be tracked using the Physical Evidence Section Chain ofCustody form.


7.1 NONE


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REMOTE FIRING

1.0 INTRODUCTION

1.1 During the course of examining a firearm, it may be determined that it wouldbe unsafe for the examiner to fire the firearm by holding it as designed. If it

is necessary to obtain test standards from this firearm, the firearm should befired remotely. The Zero-One (or a similar device) can be utilized for firinglong arms and some handguns, while the Ransom Rest (or a similardevice) can be utilized for firing handguns.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Downloading1.2.3 Primed Cases




2.3 The examiner must follow all safety recommendations set forth by the

manufacturer of the shooting device used.

2.4 Due to the potential hazard of the firearm malfunctioning or undergoing acatastrophic failure, the examiner must be stationed behind a protectiveshield or at a safe distance from the firearm when discharging the firearm.

3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE



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5.1 NONE







6.6 Set up the chosen remote firing device, as per guidelines set forth by themanufacturer, in front of the appropriate recovery system.

6.7 Place firearm in device. It is recommended that the examiner first dry-firethe firearm in the remote firing device before using live ammunition.


6.9 The examiner should consider loading no more than one (1) cartridge intothe firearm during the initial testing of the firearm.

6.10 Activate the remote device while standing behind a protective shield orwhile standing at a safe distance away from the firearm.

6.11 Obtain fired tests.

6.12 Any recovered bullets or cartridge cases used in test firing a firearm will bereturned to the investigating agency. All test fires will be consideredevidence and will be tracked using the Physical Evidence Section Chain of

Custody form.


7.1 NONE


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DOWNLOADING

1.0 INTRODUCTION

1.1 Due to the limitations of the firearms section bullet recovery devices, it may

be necessary to reduce or change the powder load of the cartridge in orderto obtain a velocity suitable for safely collecting test standards forcomparison purposes. Even with a reduced load, it may be necessary tofire the firearm remotely.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Remote Firing1.2.3 Primed Cases1.2.4 Water Tank Recovery1.2.5 Cotton Waste Recovery Box

1.2.6 Bullet Trap




3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 BALANCE/SCALE


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5.1 NONE


6.1 Pull the bullet of the cartridge using an inertia bullet puller or a reloadingpress.

6.2 Remove existing powder.

6.3 Weigh the pulled bullet.

6.4 Consult a reloading manual, such as Lyman, and obtain the powder chargefor the weight of the pulled bullet and the new velocity needed.

6.5 Weigh out the appropriate powder charge and place in existing cartridgecase.

6.6 Loosely pack a small piece of tissue or other similar material into the caseto fill the gap between the bullet and powder.

6.7 Seat the bullet back into the cartridge case using a rubber mallet or areloading press.

6.8 If appropriate powder is not available, a reduced load using 50% of theoriginal powder can be used. It should be noted that great care must betaken when performing this type of downloading. 50% downloading CANNOT be used with slow burning powders. 50% downloading CANNOT be

used with many non-canister powders.

6.9 When utilizing downloaded ammunition it is imperative that the examinercheck the barrel for obstructions between each firing. The bullet, cartridgecase, or shotshell of each test shot should be marked appropriately.


7.1 Appendix 2 - Calibration Standards


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PRIMED CARTRIDGE CASE/SHOTSHELL

1.0 INTRODUCTION

1.1 During the course of examining a firearm, it may be determined that it would

be unsafe for the examiner to fire the firearm as designed. If it is notnecessary to obtain test standards for comparison purposes, the firingcondition of the firearm can be tested using a primed empty cartridge caseor shotshell.

1.2 OTHER RELATED PROCEDURES1.2.1 Safe Firearm Handling1.2.2 Bullet Trap




3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


5.1 NONE


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6.1 Obtain a primed empty cartridge case in the desired caliber or pull the bulletof a cartridge using an inertia bullet puller or reloading press, retaining onlythe primed cartridge case.

6.1.1 For shotguns, obtain a primed empty shotshell in the desired gaugeor cut open a shotshell removing all components, retaining only theprimed shotshell. A commercial firing pin testing device may beused for shotguns.

6.1.2 For rimfire firearms, obtain a primed empty cartridge case in thedesired caliber or using pliers, remove the bullet from the cartridgecase, retaining only the primed cartridge case.



6.4 Load the primed empty cartridge case, primed empty shotshell orcommercial firing pin testing device into the chamber of the firearm and testfire in a safe direction.

6.5 Any recovered cartridge cases used in test firing a firearm will be returnedwith that firearm to the investigating agency. The tests are not consideredevidence and evidence vouchers are not required.


7.1 NONE


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CALIBER DETERMINATION

1.0 INTRODUCTION

1.1 Caliber, or the base diameter, is one of the class characteristics of a fired

bullet. The determination of caliber will aid the examiner during theidentification or elimination of a suspect firearm. If no firearm is submitted,the bullet's caliber may be used in determining the General RiflingCharacteristics of the firearm involved.

1.2 OTHER RELATED PROCEDURES1.2.1 Trace Material Examination1.2.2 GRC Utilization



2.2 Proper caution to include strict adherence to Universal Precautions and theBlood Borne Pathogen Plan must be exercised.

2.3 The use of personal protective equipment must be considered to avoid

exposure to any potential hazards.

3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 Comparison Microscope4.2 Stereo Microscope4.3 Calipers/Micrometer


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5.1 NONE


6.1 The following may be utilized to determine the caliber of any fired bullet.The condition of the bullet will determine which steps can be used.

6.1.1 Compare the base diameter of the evidence bullet directly withknown test standards.

6.1.2 Measure the base diameter of the evidence bullet using a measuringdevice and compare this measurement with known measurementspublished in reference literature.

6.1.3 Determine the number and widths of the land and groove signaturesand compare to Appendix G, Table 6, of the AFTE Glossary or use amathematical formula.

6.1.4 Physical characteristics of the evidence bullet, such as weight, bulletshape, composition, nose configuration, and number and placementof cannelures, may aid in caliber determination.


6.2.1 Caliber is written as a numerical term without the decimal point. Ifthe base is mutilated, the examiner may only be able to determinethat the evidence is consistent with a range of calibers or that the

caliber cannot be determined.





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STEREO MICROSCOPE MEASURING EYEPIECE

1.0 INTRODUCTION

1.1 One of the class characteristics used in the discipline of firearms

identification is the width of the land impressions and groove impressions.These measurements aid the examiner during the identification orelimination of a suspect firearm. If no firearm is submitted, thesemeasurements will be used in determining the General RiflingCharacteristics of the firearm involved. Several instruments can be used toobtain these measurements. The stereo microscope measuring eyepieceprocedure utilizes a stereo microscope equipped with a measuringeyepiece.

1.2 OTHER RELATED PROCEDURES1.2.1 Trace Material Examination

1.2.2 GRC Utilization




2.3 The use of personal protective equipment must be considered to avoidexposure to any potential hazards.

3.0 PREPARATION

3.1 NONE


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4.0 INSTRUMENTATION

4.1 Stereo Microscope


5.1 NONE


6.1 In measuring a fired bullet to determine the width of the land impression orthe groove impression, it is paramount that the points used for beginningand ending a measurement comply with the discipline-wide practice. Thispractice utilizes the anchor points shown below.

6.1.1 The fired bullet in question is either held or mounted on a steadysurface beneath the stereo microscope.

6.1.2 The land impression of the fired bullet is placed in a vertical positionwith both of the anchor points corresponding to points on thealignment grid and record the measurement to the nearest hundredthor thousandth of an inch or appropriate measurement.

6.1.3 Repeat the above utilizing the groove impression.


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6.2.1 It may be necessary to measure several of each land and grooveimpression in order to record a reliable measurement.





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GRC UTILIZATION

1.0 INTRODUCTION

1.1 The data from the FBI's General Rifling Characteristics File can be utilized

when attempting to determine a list of possible firearms that could havefired an evidence bullet when the correct firearm was not submitted.

1.2 OTHER RELATED PROCEDURES1.2.1 Trace Material Examination1.2.2 Stereo Microscope Measuring Eyepiece


2.1 This procedure involves hazardous materials, operations and equipment.This procedure does not purport to address all of the safety problems

associated with its use. It is the responsibility of the individual examiner topractice the appropriate safety and health practices. Proper caution mustbe exercised and the use of personal protective equipment must beconsidered.



3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 NONE


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5.1 NONE


6.1 The General Rifling Characteristics File can be accessed using various PCsoftware or the current printout of the file.

6.2 Follow the operating instructions listed specifically within each of the abovesystems utilizing the caliber and rifling characteristics of the evidence bullet.

6.3 INTERPRETATION OF RESULTS:6.3.1 The GRC File is an investigative aid and should not be construed as

an all-inclusive list of firearms available with those particular riflingcharacteristics.




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WAD DETERMINATION

1.0 INTRODUCTION

1.1 By examining wad, the examiner may be able to determine the gauge,

manufacture, and if the wad contains markings suitable for comparison.



2.1 This procedure involves hazardous materials, operations and equipment.This procedure does not purport to address all of the safety problemsassociated with its use. It is the responsibility of the individual examiner to

practice the appropriate safety and health practices. Proper caution mustbe exercised and the use of personal protective equipment must beconsidered.



3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 Comparison Microscope4.2 Stereo Microscope4.3 Caliper


5.1 NONE


6.1 Determine gauge by;


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6.1.1 Directly comparing evidence to known laboratory standards of similarmanufacture or composition by comparing the base of evidence tothe bases of the standards until a similar size is found.

6.1.2 Gauge can also be determined by measuring the base diameter ofthe wad and comparing these measurements to knownmeasurements.

6.2 Measurements may be obtained by utilizing a;6.2.1 Caliper6.2.2 The stereo microscope with measuring eyepiece

6.3 Manufacturers data can be determined by locating information stamped intothe wad or by comparing the wad to known laboratory standards.

6.4 Microscopic examination may reveal striations suitable for identification ofthe wad back to the shotgun that fired it.

6.5 If evidence shotshells are submitted, it may be necessary to disassembleone in order to determine the characteristics of the internal components.

6.6 Record all information on the appropriate worksheet.

6.7 INTERPRETATION OF RESULTS:6.7.1 If the wad is mutilated or soaked with blood or other body fluids, the

examiner may not be able to specifically determine gauge size. Theexaminer should also recognize that some manufacturers mayduplicate the design of another manufacturer.





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SHOT DETERMINATION

1.0 INTRODUCTION

1.1 By examining recovered shot, the examiner may be able to determine the

actual shot size. The determined size can then be compared to the shotsize loaded in submitted unfired shotshells or to the size that the submittedshotshell casing was marked to have contained.



2.1 This procedure involves hazardous materials, operations and equipment.

This procedure does not purport to address all of the safety problemsassociated with its use. It is the responsibility of the individual examiner topractice the appropriate safety and health practices. Proper caution mustbe exercised and the use of personal protective equipment must beconsidered.



3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 Comparison Microscope4.2 Stereo Microscope4.3 Caliper4.4 Scale/Balance


5.1 NONE



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6.1 The examiner may use one or all of the below techniques to determine shotsize.

6.1.1 Visual/Microscopic Comparison

6.1.1.1 Determine the total number of pellets received.

6.1.1.2 Determine the composition of the pellets.

6.1.1.3 Determine the number of pellets suitable for comparisonpurposes. Make note if pellet sizes all appear to be similarin size. If several different sizes are present, determineeach specific size.

6.1.1.4 Compare laboratory standards of known shot sizes side byside with the evidence pellets until a known shot size isdetermined. A stereo microscope may aid in thisdetermination. This should be done one size at a time toavoid errors.

6.1.1.5 Record findings on worksheet.

6.1.2 Comparison by Weight

6.1.2.1 Record the total number of pellets received.


6.1.2.3 Determine the number of pellets suitable for weighing.

Make note if pellet sizes all appear similar. If several sizespresent, determine each specific size.

6.1.2.4 Weigh the pellets in grains.

6.1.2.5 Divide weight of pellets by total number weighed.

6.1.2.6 Consult known pellet weight charts and determine shotsize which corresponds to evidence shot.

6.1.2.7 Record findings on appropriate worksheet.

6.1.2.8 The weight of the evidence pellets can also be directlycompared to weight of standards using the same numberof pellets until a similar known weight is obtained.

6.1.3 Measuring Pellet Size


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6.1.3.1 Determine the total number of pellets received.


6.1.3.3 Determine the number of pellets suitable for comparisonpurposes. Make note if pellet sizes all appear to be similarin size. If several different sizes are present, determineeach specific size.

6.1.3.4 Choose the best specimen and measure the diameter.Record in hundredths or thousandths of an inch or theappropriate measurement.

6.1.3.5 Consult known pellet size charts and determine shot sizewhich corresponds to evidence shot.





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PHYSICAL EXAMINATION & CLASSIFICATION OF FIRED

PROJECTILES1.0 INTRODUCTION

1.1 The initial examination of projectile evidence will include the completion of a

worksheet. These worksheets will include the physical description of theprojectile(s) and will serve as a source to document the condition of theevidence as received and any tests or comparisons performed.

1.2 OTHER RELATED PROCEDURES1.2.1 Trace Material Examination1.2.2 Stereo Microscope Measuring Eyepiece1.2.3 Caliber Determination




2.3 The use of personal protective equipment must be considered to avoid

exposure to any potential hazards.

3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 Comparison Microscope4.2 Stereo Microscope4.3 Caliper

4.4 Scale/Balance


5.1 NONE



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6.1 A worksheet will be completed on all projectiles. This will include noting thefollowing:

6.1.1 Laboratory Case Number6.1.2 Item Number6.1.3 Package Description6.1.4 Physical Description and Condition of the Projectile(s)6.1.5 Number of projectile pieces6.1.6 Projectile Caliber/Shot Size/Wad Size6.1.7 Projectile(s) Weight6.1.8 Number of cannelures and style (if present)6.1.9 Projectile type and style6.1.10 Base description6.1.11 Brand of ammunition6.1.12 General Rifling Characteristics

6.1.12.1 Number of lands and grooves on fired projectile6.1.12.2 Direction of twist6.1.12.3 How many characteristics seen6.1.12.4 How class characteristics determined6.1.12.5 Measured width of the land impressions when no firearm is

submitted as evidence or bullet does not match test firedbullets from the submitted gun

6.1.12.6 Measured width of the groove impressions when nofirearm is submitted as evidence or bullet does not matchtest fired bullets from the submitted gun

6.1.13 Where projectile marked by examiner6.1.14 Description of and placement of other investigators markings on

projectile6.1.15 Trace evidence observed or collected

6.1.16 If the projectile was bent for examination6.1.17 If the projectile was cleaned for examination6.1.18 Examiners Initials6.1.19 Date of Examination6.1.20 At the discretion of the examiner, any additional information that

might be useful can be documented.





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PHYSICAL EXAMINATION & CLASSIFICATION OF CARTRIDGES &FIRED CARTRIDGE CASES

1.0 INTRODUCTION

1.1 The initial examination of any cartridge or fired cartridge case evidence will

include the completion of a worksheet. These worksheets will include thephysical description of the cartridge or fired cartridge case and will serve asa source to document the condition of the evidence as received and anytests or comparisons performed.

1.2 OTHER RELATED PROCEDURES1.2.1 Trace Material Examination1.2.2 Stereo Microscope Measuring Eyepiece1.2.3 Caliber Determination





3.0 PREPARATION

3.1 NONE

4.0 INSTRUMENTATION

4.1 Comparison Microscope4.2 Stereo Microscope

4.3 Caliper4.4 Scale/Balance



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5.1 NONE


6.1 A worksheet will be completed on all cartridges and fired cartridge cases.This will include noting the following if applicable:

6.1.1 Laboratory Case Number6.1.2 Item Number6.1.3 Package Description6.1.4 If any trace material is present

swifs firearms and toolmarks procedures manual v2.2 (05.29.2008) 130 pages

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