Gunshot Wounds and Violent Assaults Forensic Aspects for the Trauma Specialist

Transcription

1 Gunshot Wounds and Violent Assaults Forensic Aspects for the Trauma Specialist 28 th Annual David Miller Trauma Symposium Presented by Michael S. Maloney, MFS

2 Our primary crime scene is often moved and out of our control EMS Ambulance Trauma Center Emergency Room

3 Our primary crime scene is often examined without an eye towards forensic evidence

4 If the Trauma Specialist is familiar with forensic evidence could an approach be taken that documents or preserves evidence without impacting patient care?

5 What evidence may be on the body? Biological blood semen saliva urine Trace hairs fibers gunshot residue glass soil Touch DNA where was the body handled? Wound and its morphology single edge double edge pattern injury gsw

6 Other Factors Wound appearance: pre-intervention Wound appearance: post-intervention Blood flow patterns on clothing/skin Blood spatter patterns on clothing skin Initial blood draw: pristine toxicology Drugs Alcohol

7 Why is this important? The physical health of the victim is always of paramount concern. The mental health of the victim cannot be allowed to take a back seat eventually closure or moving past the incident is aided with successful criminal or civil prosecution of the perpetrator. Additionally, successful prosecution and incarceration removes serial offenders from impacting the same or different victims.

8 O.J. Simpson

9 Wound Appearance: Post Intervention

10 Our Challenge from the Forensic Side

11 Entrance injury photographic overlaid on model

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13 Circular pattern on skin in association with entrance wound

14 Axis between possible circular pattern injury and entry wound demonstrated

15 Possible pattern injury from recoil guide

16 Ruining every cop show you ever watched or murder mystery you ever read UNDERSTANDING FIREARMS AND BALLISTICS

17 Getting the Terminology Right!

18 Handguns - Pistols Revolver Semi-Automatic

19 Clip Clip

20 Magazine

21 Cartridge Cases Casings

22 Shells Shotshells

23 Headstamp Headstomp

24 Ballistics Internal - within the weapon External - outside of the weapon Terminal - within the target structure (your area of specialty)

25 INTERNAL BALLISTICS

26 Ejector Extractor Ejector Breech Face Firing Pin Copyright: Bevel, Gardner & Associates 2012 Revised Mar 2012

27 Extractor Ejector 1 3 Ejector 2 Firing Pin & Breech Face Copyright: Bevel, Gardner & Associates 2012 Revised Mar 2012

28 Primers Unfired primer--no microscopic marks Fired primer with firing pin and breech face marks Copyright: Bevel, Gardner & Associates 2012 Revised Mar 2012

29 Rifling Copyright: M. Maloney 2012 Revised Mar 2012

30 Projectiles Unfired bullet, smooth sides Fired bullet -rifling impressions and unique microscopic striae Copyright: M. Maloney2012 Revised Mar 2012

31 Terminal Ballistics WEAPONS DYNAMICS & WOUND DYNAMICS

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33 25

34 ENTRANCE WOUNDS

35 Circular or Elliptical Entrance Abrasion collar or ring Wound Discolored circle around the entrance wound May overlap bullet wipe Caused by the abrasion of skin by the bullet as it pushes through entrance Perpendicular (symmetrical), or tangential (wider on one side)

36 Star shaped entrance wound, common with pressed contact over bone

37 DISTANCE FROM TARGET

38 Contact Wound Margin Abrasion Heat Effect Soot in Wound Track Possible complete or partial muzzle impression Possible Cherry Red discoloration

39 Close Distance Margin Abrasion Soot Gray or black, dense carbon Product of burning gun powder May be accompanied by stippling Can be washed off easily

40 Intermediate Distance Margin Abrasion Stippling Small punctate lesions surrounding a wound from burning and unburned powder Live victims--reddish brown vital reaction Dead victims--gray or yellow, since no vital reaction Cannot be washed off Pattern size increases with distance

41 Powder Shapes Manufacturers use different powder shape and size to control rate of burn and pressure peak

42 Gun Powder Disc Rod/Disc Sheet Flake

43 Bullets & The Bullet Effect on the Body Mass v Energy 45

44 Mass Energy

45 Round Nose

46 Semi-Jacketed

47 Hollow Points 56

48 Expanding Hollowpoint

49 R.I.P. Another day. Another Gimmick 50

50 Wound Track Permanent Cavity Tissue directly damaged by the projectiles passage May be larger in diameter than the projectile based upon destabilization/tumbling Temporary Cavity Expansion of high energy wave through the tissue surrounding the permanent cavity. The size of the temporary cavity is directly proportional to the amount of energy transferred from the projectile to the surrounding tissue

51 Permanent Cavity

52 Permanent Cavity

53 Temporary Cavity

54 Temporary Cavity

55 Temporary Cavity

56 Graze Wounds

57 Graze Wound Bullet strikes at a shallow angle Produces an elongated area of abrasion Without actual perforation or tearing of the skin

58 Graze Wounds

59 Dog Balls

60 A Ninja, A Rifle, And a Water Tower A Ninja, A Rifle and a Water Tower

61 Attack!

62 Testicles

63 Graze Wounds

64 Testicular Orientation

65 Forensic Simulation (No Dogs were injured in this simulation though the human fell on his hind quarters pretty hard)

66 ?