Firearm and Tool mark identification

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Firearm and Tool mark identification

• A GENERAL PRIMER
• Genesee County Bar Association
• Criminal Law Seminar-2013

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COOL, ATTRACTIVE PEOPLE
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REAL LIFE

• CSI-BRIDGEPORT

AWKWARD NERDS
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Major Historical Events in Early Firearm and Tool
Mark Identification.

• Brownsville Affray, 1907
• Prof. Balthazard, 1912-Photomicrograph
  Comparisons
• Stielow Case, 1915
• Sacco and Vanzetti Case, 1920
• Waite/Goddard Partnership 1924-Use of the
  Comparison Bridge Microscope
• St. Valentines Day Massacre of 1929
• Opening of the Chicago Crime Lab at Northwestern
  University in 1930 by Calvin Goddard. First ever
  Public Forensic Science Laboratory.
• 1932 FBI Lab opens with one person, who was an
  agent (Charles Appel) trained at Northwestern by
  Calvin Goddard and co. Appel soon after handled
  the Lindburgh baby case as a questioned document
  examiner.

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Scientific Studies

• 1920s-1930s
• In the U.S., the work of individuals such as Col.
  Calvin Goddard, J. Howard Matthews, and Maj.
  Julian Hatcher provide study and insight into the
  science supporting Firearm and Tool Mark
  Identification. The examination methodology is
  standardized in terms of Classification and
  Identification, and texts are popularized for use
  and training of Firearms Examiners.
• In Europe, the work of individuals such as French
  Professor Victor Balthazard, Robert Churchill,
  Sir Gerald Burrard, and Col. H.W. Todhunter
  further the practice through study and the
  writing of subject matter.
• Courts around the country (and in Europe) begin
  to commonly accept forensic firearm and tool mark
  expert testimony by the 1940s.

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Contemporary Scientific Studies

• 1955 A.A. Biasotti completes his 97 page thesis
  concerning Bullet ComparisonsA Study of Fired
  Bullets Statistically Analyzed.
• Biasotti goes on to publish several other very
  important statistical studies concerning striated
  tool marks on fired bullets throughout the 50s,
  60s, and early 70s.
• Other examiners expand on these studies, which
  create statistical foundations for striated
  toolmarks.

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Contemporary Scientific Studies

• 1969 Association of Firearm and Toolmark
  Examiners (AFTE) is chartered. The AFTE Journal
  is popularized as a peer-reviewed scientific
  journal concerning the relevant field.
• 1990s-2000s Statistical studies concerning
  algorithmic databasing of IMC, impressed
  toolmarks, 3d imaging, striated toolmarks,
  stochastic probability, and more continue to be
  produced. Academia begins to again become more
  involved due to the prevalence of Forensic
  Science Programs at universities.

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Battlefield Forensics

• Firearm Identification is firmly lodged in
  wartime battlefield forensic science and
  intelligence. Mobile and temporary labs are
  staffed by USACIL (US Army Criminal Investigation
  Laboratory) in the middle east theatres, and
  USACIL has for 70 years intermittently operated
  several Forensic Science Laboratories in the US,
  the Phillippines, Japan, and Vietnam.
• In the first years of the Iraq/Afghanistan wars,
  firearm and toolmark examiners were privately
  offered upwards of 250,000 tax free to work one
  year stints within the theatre of operations.

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Identification Criteria

• SWGGUN and AFTE
• (Relevant Scientific Community)

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• 2.2
• SWGGUN endorses the Association of Firearms and
  Tool Mark Examiners (AFTE) Theory of
  Identification definition as set forth in the
  AFTE Journals (July 1992 Volume 24, Number 3 and
  Fall 2011 Vol. 43, No. 4) to be the generally
  accepted Criteria for Identification
• 2.2.1
• The theory of identification as it pertains to
  the comparison of toolmarks enables opinions of
  common origin to be made when the unique surface
  contours of two toolmarks are in sufficient
  agreement.
• 2.2.2
• This sufficient agreement is related to the
  significant duplication of random toolmarks as
  evidenced by the correspondence of a pattern or
  combination of patterns of surface contours.
  Significance is determined by the comparative
  examination of two or more sets of surface
  contour patterns comprised of individual peaks,
  ridges and furrows. Specifically, the relative
  height or depth, width, curvature and spatial
  relationship of the individual peaks, ridges and
  furrows within one set of surface contours are
  defined and compared to the corresponding
  features in the second set of surface contours.
  Agreement is significant when the agreement in
  individual characteristics exceeds the best
  agreement demonstrated between toolmarks known to
  have been produced by different tools and is
  consistent with agreement demonstrated by
  toolmarks known to have been produced by the same
  tool. The statement that sufficient agreement
  exists between two toolmarks means that the
  agreement of individual characteristics is of a
  quantity and quality that the likelihood another
  tool could have made the mark is so remote as to
  be considered a practical impossibility.
• 2.2.3
• Currently the interpretation of
  individualization/identification is subjective in
  nature, founded on scientific principles and
  based on the examiners training and experience.

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• Random/Stochastic Process
• Chip Formation
• Microscopic Individuality!

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• Chip Formation-Chip Types

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• Tool Velocity and Chips

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• Chip Packing!

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Pattern Matching

• One reason humans are such a successful species
  is because we are so good at recognizing
  PATTERNS. We recognize the faces of loved ones
  in crowds, we remember faces instead of names.
  Look at Tetris, child block games, Rubicks
  cubes, the list goes on and on.
• Firearm and Tool Mark Identification relies on
  Pattern Matching.
• Butthis type of pattern matching does not rely
  on memory! It is performed in REAL TIME on a
  comparison bridge microscope!

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Comparison Bridge Microscope
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Class Characteristics

• Class Characteristics are measureable features of
  a specimen which indicate a restricted group
  source. They result from design factors, and are
  therefore determined prior to manufacture.
• For Fired Bullets Rifling twist, width, type
  (conventional or polygonal), number of grooves.
• For Fired Cartridge Cases Shape of firing pin,
  shape of firing pin aperture, ejector/extractor
  shape and position, type of machining marks
  (arched/linear/concentric), etc.

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GLOCK Rectangular Firing Pin Aperture

• Example of a Class Characteristic

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• Comparison Bridge Microscopic Comparison between
  Two Cartridge Cases fired in a Glock

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• GLOCK Pistol

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Rifling Width Class DifferenceElimination
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• Class Characteristics allow the informed expert
  to easily ELIMINATE firearms as having fired
  unknown exemplars if the class is different. We
  dont hear about this too often in court because
  when this is the case, the evidence usually is
  exculpatory in nature and the investigation never
  makes it that far.
• If the class characteristics produced by the tool
  or firearm are similar, the expert should not
  eliminate the tool or firearm as a possible
  source-even if the individual microscopic
  characteristics are different. This is because
  surfaces can wear and change over time, and can
  change extensively via misuse or intentional
  abuse. Therefore, for instances where
  known/unknown class characteristics are similar,
  the outcome may be either inconclusive or an
  identification. Some out-state labs have a
  policy where they WILL eliminate based on
  differences in individual characteristics. This
  is a point of contention.

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Subclass

• Subclass characteristics are discernible surface
  features of an object which are more restrictive
  than Class Characteristics in that they are
  produced incidental to manufacture, are
  significant in that they relate to a smaller
  group source (subset to the class that they
  belong), and can arise from a source which
  changes over time.
• Subclass characteristics tend to be gross in
  nature (not fine or minute).
• EXAMPLE Smith Wesson MIM firing pins
• Examiners learn about and publically share
  information concerning subclass characteristics
  among units, departments, and particularly
  through the AFTE Journal, the AFTE Conference,
  and the AFTE Forums.

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Individual Microscopic Characteristics

• Allow for firearm and toolmark identification.
  Absolutely random in nature (cannot be
  predicted/from a stochastic process).
• Are created through chip formation, random
  imperfections caused by chips caught within
  working surfaces, differences in hardness of
  steel, tool speed (ex. Drilling), accidental
  imperfections from firing and handling/use, and
  other mechanical means.

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Lone Characteristic Within the FPI of Two Fired
Cartridge Cases
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• Lack of Significant Agreement Between IMC on Two
  Fired Cartridge Cases

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Metal Injected Molding (MIM) Produces a Subclass
Mold Relic at the Break Line

• These relics mimic individual characteristics,
  and while shared by a unique subset of firing
  pins (pins made by a specific mold), it is a
  major cause for concern.

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First Step Determining Tool Class
Characteristics
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Different Class!
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TOOL MARK IDENTIFICATION

• STRIATED IMPRESSION

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Opposite BladeMore Agreement
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• VERY Similar Class (Hi-Point most likely). NO
  Matching Individual Characteristics

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One Group of Identified Cartridge Cases had
Reamer Chatter Marks that Resembled Fluting
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Same Firearm, Consecutive Tests!!! Uh-oh!
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FIREARMS IDENTIFICATION

• STAMPED IMPRESSION
• (Firing Pin Impression)

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Another Firing Pin Identification
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MSP Firearms Unit Facts

• All examiners are members of the Association of
  Firearm and Tool Mark Examiners (AFTE)
• All examiners undertake, and must pass--a two
  year program consisting of study and practical
  training. The program is modeled after the AFTE
  training protocols. Two have been trained at the
  ATF-NFEA (National Firearms Examiner Academy),
  which is a very prestigious program.
• Examiners are proficiency tested twice per year
  by an outside source.
• Examiners work in a laboratory that is accredited
  to ISO 17025 Standards by ASCLD-LAB, and their
  units are audited on a yearly basis.
• Measurements that Matter utilize NIST
  calibrated equipment, traceable to the BIPM
  (Bureau International des Poids et Measures).
• All examiners abide by two codes of ethics The
  AFTE Code of Ethics and the ASCLD Guide to
  Professional Responsibility.
• The former also requires two AFTE members who
  disagree to attempt a constructive agreement
  prior to any testimony.

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Choosing an Independent Expert

• If ethics are important to you (I hope so), is
  the independent expert a member in good standing
  with AFTE?
• Experience within an actual laboratory setting is
  important. Have you vetted the independent
  expert? Do you know anyone in your state who can
  vouch for him or her? Beware experts from other
  states who are not members of AFTE and have
  limited track records. Do your homework!!
• Remember that a presented expert may lack
  formalized training , may not be proficiency
  tested (or may never have been), and may not
  utilize any type of technical or peer review.
  Look for an expert who possesses these qualities.
• There are many Independent Experts from around
  the country who fit the qualities you might be
  looking for. They do work in civil and criminal
  cases. The following list is a good place to
  start they are all Distinguished Members of
  AFTE
• http//www.afte.org/distmemberreferal.htmmidwest
  

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Contacting an MSP Scientist

• Jim Piazza, Barry Wolf, Barney Whitesman, Pat
  Kirby, Lee Sturtz, and other Mid-Michigan Defense
  Counsel have personally contacted me prior to
  trial to discuss their cases.
• Only a handful of prosecutors in a 14 county
  service area frequently contacted me prior to
  trial. Very few met with me to go over the
  report findings and discuss significance/etc.
• There is nothing in our operations policy which
  precludes talking with Defense Counsel about
  casework that has been reported. My employees
  are friendly, dedicated, and helpfulif you
  actually ask.
• Please dont be a confrontational jerk if you
  contact my employees outside of the courtroom
  context. You dont need to be.

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Crafting Your Plan

• ASK the Forensic Scientist! If you are a defense
  counselor worried about letting your cat out of
  the bag prior to trial, talk to the expert
  shortly before the witness hits the stand. We
  spend a lot of time waiting in the hallway.
• CALL or MEET with the Firearm Examiner if you
  can. Educate yourself about the case. It is
  FREE.
• UNDERSTAND that the Examiner frequently knows
  much less about the case particulars than you
  think. Typically, the only cases where the
  examiner has investigative case knowledge of any
  depth are those where the examiner worked the
  crime scene. It can therefore be helpful to
  speak to the examiner to discover fact-based
  opinions that could assist your prosecution or
  your defense.

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Asking the Right Questions

• Subjectivity-This is an Opinion, correct?
• Practical vs. Absolute Certainty-Explain
• Inconclusive Findings and the prevalence of
  firearms that could have fired this bullet etc
  (Thousands/Hundreds of Thousands/Millions??)
• Can you load and fire this bullet in another
  caliber cartridge (i.e. a 115 grain 9mm Luger
  bullet in a .357 Magnum case)?
• Explore the Possibilities--How could this have
  happened/are there other things that could
  account for this occurrence?
• Your testing can only place an object at a scene,
  not a person at a scene, correct?
• www.firearmsid.com