530 likes | 918 Views
Guns: Ballistics and Politics. Chief Talk Winter 2008 Jeffrey Salerno. Agenda. Burden of Gun Violence Ballistics Basics Public Health Data Behind Gun Control. Gun Violence at BMC. Simple IBEX query for GSW from Christmas 2007 to Christmas 2008 279 cases 19 deaths
E N D
Guns: Ballistics and Politics Chief Talk Winter 2008 Jeffrey Salerno
Agenda • Burden of Gun Violence • Ballistics Basics • Public Health Data Behind Gun Control
Gun Violence at BMC • Simple IBEX query for GSW from Christmas 2007 to Christmas 2008 • 279 cases • 19 deaths • 4 unknown black males • Most are under 25
US Burden of Gun Violence • 30000 deaths from firearms annually • 17000 suicide • 12000 homicide • 789 accidental • Medical Costs: 2.3 billion annually • Rates of homicide rising among young black males (see graphs) http://www.disastercenter.com/cdc/Age%20of%20Deaths%20113%20Causes%202005.html Homicides among black males spike by Maria Cramer, The Boston Globe. Dec 29th 2008 Philip Cook et al., The Medical Costs of Gunshot Injuries in the United States, 282 JAMA 447 (Aug. 4, 1999).
US Burden of Gun Violence • 30000 deaths from firearms annually • 17000 suicide • 12000 homicide • 789 accidental • Medical Costs: 2.3 billion annually It is not that the FBI figures (showing flat or decreasing national homicide rates) tell an inaccurate story about crime trends in America. Rather, they obscure the divergent tale of two communities—one prosperous and safe, the other poor and crime-ridden. The truth behind the fears and concerns of the nation’s underclasses about crime and violence lies deep beneath the surface of the FBI statistical report. -James Alan Fox, Northeastern http://www.disastercenter.com/cdc/Age%20of%20Deaths%20113%20Causes%202005.html Homicides among black males spike by Maria Cramer, The Boston Globe. Dec 29th 2008 Philip Cook et al., The Medical Costs of Gunshot Injuries in the United States, 282 JAMA 447 (Aug. 4, 1999).
Firearm Mortality: Suicides • Suicide • ~50 people per day commit suicides with firearms • Many suicides are impulsive acts • Especially for the young Hemmingway, Cobain, and Hunter S Thompson all died by self-inflicted shotgun wounds
Firearm Mortality: Homicide • Suicide • Homicide • ~40 people per day are murdered with firearms • Gun murders account for ~60% of murders
Firearm Mortality: Accidents Greg Lemond missed 2 Tour de France races after getting accidentally shot, Speke shot himself to death the day before presenting his discovery of the source of the Nile to the Royal Geographic Society. Cheney and Bobby Knight have both accidentally shot people with shotguns. • Suicide • Homicide • Accidental • 2-3 accidental firearm deaths per day • 10x that number of non-fatal injuries
Case 1: Shot with a BB • 51yo M with HIV, on HAART was trimming his hedge when he heard the sound of an air rifle and felt a sharp pain in his RLQ • BP: 122/79, Pulse: 62, Resp: 18, Temp: 98.8, O2 sat: 97 on 2L • Small puncture wound in the RLQ
Case 1: Shot with a BB • 51yo M with HIV, on HAART was trimming his hedge when he heard the sound of an air rifle and felt a sharp pain in his RLQ • BP: 122/79, Pulse: 62, Resp: 18, Temp: 98.8, O2 sat: 97 on 2L • Small puncture wound in the RLQ CT showed 5mm metallic object lodged against the sacral spine and free air. He went for ex-lap. Even small caliber, low velocity arms can cause significant morbidity.
Bullets • Standard Bullet • Made of soft lead • Tend to deform on impact • Can fragment
Bullets • Standard Bullet • Made of soft lead • Tend to deform on impact • Can fragment • Jackets • Jacket protects bullet during firing and allows higher muzzle velocities • Renders them non-deformable
Bullets • Standard Bullet • Made of soft lead • Tend to deform on impact • Can fragment • Jackets • Jacket protects bullet during firing and allows higher muzzle velocities • Renders them non-deformable • Expanding Bullets • Hollow Point • Semi-Jacketed
A word on rifling • Bullets fired from a rifled barrel have axial stability from the spin • Spinning bullets stop when they hit their target and dastabilize • Destabilization leads to tumbling
A word on rifling • On X-ray rifled bullets (white arrow) often have spun 180 degrees during their path thru tissue and point backwards toward the entry point (black arrow)
Black Tallon, Cop Killer, Starfire • Expanding round for handguns • Involved in the 101 California Street shootings in San Fran • Opposed by ACEP as sharp pieces could pierce gloves • Winchester voluntarily pulled the ammunition from the market in 2000 • The "Ranger SXT" sold today by Winchester is essentially the same ammunition without the black coating • The running joke is that SXT stands for "Same eXact Thing"
Terminal Ballistics: Velocity • medium velocity weapons travel 1100 to 2000 feet/second • Usually small handguns • high velocity weapons travel >2000 feet/second • Rifles and large handguns • Ref: speed of sound 1087 feet/second E=1/2MV2
Terminal Ballistics: Velocity • Low velocity projectiles often fail to penetrate bone or fascia. • May have non-linear paths of travel, bounce off bone or fascia, stay in fat or SQ tissue • This man was shot in the elbow and bullet stopped at the level of the wrist
Terminal Ballistics: Velocity • Medium and high velocity weapons cause tissue disruption beyond the path of the bullet • Usually have linear paths thru tissue
Terminal Ballistics:Boney Damage • Low Velocity • Often stopped by large bones • May Transfer energy into a fragment-type fracture Newton CD and Numaker DM. The Textbook of Small Animal Orthopedics. Accessed at CHAPTER 36: OPEN FRACTURES AND GUNSHOT INJURIES. http://cal.vet.upenn.edu/projects/saortho/chapter_36/36mast.htm
Terminal Ballistics:Boney Damage • High Velocity • Often shatters bone • Can create secondary projectiles Newton CD and Numaker DM. ThTextbook of Small Animal Orthopedics. Accessed at CHAPTER 36 PEN FRACTURES AND GUNSHOT INJURIES. http://cal.vet.upenn.edu/projects/saortho/chapter_36/36mast.htm
Terminal Ballistics:Soft Tissue Damage • permanent cavitation (the hole left by the bullet) • temporary cavitation (the tissue displaced as the bullet passed) • May be significant in tissues without significant elastic component (liver or brain vs muscle) • Pressure Wave • Nerve stunning 3.^ Suneson A, Hansson HA, Seeman T: Central and Peripheral Nervous Damage Following High-Energy Missile Wounds in the Thigh. The Journal of Trauma. 28(1 Supplement):S197-S203; January 1988.4.^ Suneson A, Hansson HA, Seeman T: Pressure Wave Injuries to the Nervous System Caused by High Energy Missile Extremity Impact: Part I. Local and Distant Effects on the Peripheral Nervous System. A Light and Electron Microscopic Study on Pigs. The Journal of Trauma. 30(3):281-294; 1990.5.^ Suneson A, Hansson HA, Seeman T: Pressure Wave Injuries to the Nervous System Caused by High Energy Missile extremity Impact: Part II. Distant Effects on the Central Nervous System. A Light and Electron Microscopic Study on Pigs. The Journal of Trauma. 30(3):295-306; 1990.
Ballistics Basics: Shotguns • Initial pellet velocity decreases quickly and spread increases with distance from the target • Most lethal SGWs occur at close range (<3 yards) • The diameter of the spread can help you determine the range and velocity at impact
Ballistics Basics: Shotguns • Arterial Embolization • 1968 review of 33 cases of arterial bullet embolism: • 2 carotid embolizations • 7 UE embolizations • 24 LE embolizations • embolization to the heart and lung have been reported • Wadding • Can be driven into the wound at close range • Acts as a nidus for infection • Air • At close range air driven into the wound can cause significant soft tissue damage
Case 2: 8yo GSW to abdomen • Liquarry Jefferson • Sunday June 24th, 2007 11:29PM • 8yo M shot in the abdomen • Pulse: 105, Resp: 46, O2 sat: 93 RA • Wounds to LLQ (with extruded bowel) and R flank
Case 2: 8yo GSW to abdomen • Liquarry Jefferson • Sunday June 24th, 2007 11:29PM • 8yo M shot in the abdomen • Pulse: 105, Resp: 46, O2 sat: 93 RA • Wounds to LLQ (with extruded bowel) and R flank • Died in the OR • Mother claimed armed intruders had forced their way into the house and shot her son • In fact shot by his 7yo cousin • Gun (9mm) owned by his 16yo half brother. It was found under the stairs in the apartment
America’s Arsenal“A well regulated militia” • The 1994 National Survey of the Private Ownership of Firearms (NSPOF) indicated that American adults owned approximately 192 million working firearms, an average of one per adult Cook PJ, Ludwig J. Guns in America: results of a comprehensive national survey on firearms ownership and use. Washington, DC: US Department of Justice, National Institute of Justice, 1996.
America’s Arsenal“A well regulated militia” • Gun ownership grew significantly in the later half of the last century • 70% of the guns sold in the 20th century were bought after 1960 • There is a trend away from long guns, toward handguns • 1960: 27% of guns sold were handguns • 1994: 54% of guns sold were handguns Millions Hemenway, David. Private Guns, Public Health
America’s Arsenal“A well regulated militia” • 34.0% of gun owners keep their guns loaded and unlocked. • One sixth of handgun owners regularly carry their weapons • approximately half in their cars Millions MMWR: First Reports Evaluating the Effectiveness of Strategies for Preventing Violence: Firearms LawsFindings from the Task Force on Community Preventive Services. Oct 3, 2003. Accessed at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5214a2.htm
The Secondary Market • Most gun transactions are completely unregulated • Unlicensed private sellers are permitted by law to sell privately-owned guns at gun shows, or at private locations, in 24 states Cook PJ and Ludwig J Guns in America: Results of a Comprehensive National Survey on Firearms Ownership and Use. Washington, DC. Police Foundation 1996.
America’s Arsenal“A well regulated militia” • 4.5 million new firearm sales each year • 2 to 4.5 million secondhand firearms sales each year • 0.5 million firearms are stolen each year • The total number of firearms transactions could be as high as 9.5 million per year. MMWR: First Reports Evaluating the Effectiveness of Strategies for Preventing Violence: Firearms LawsFindings from the Task Force on Community Preventive Services. Oct 3, 2003. Accessed at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5214a2.htm
History of Federal Gun Laws • 1791 First Amendment • 1934 National Firearms Act • Required registration of machine guns • 1968 Gun Control Act • Prohibited sale to felons, fugitives, psychotics • Restricted importation of Sat Night Specials • Limited sale of automatic weapons • 1993 Brady Bill • Required background checks • 1994 Federal Assault Weapons Ban • 2004 Assault weapon ban expired
Public Health Model • “From 1920 through the 1950s, the traffic safety establishment perpetuated the belief that drivers were responsible for accidents….Drivers were suspect, while the actions of engineers and automakers were unquestioned. [The proposed remedies] dealt with eliminating driver fault. Federal policy reflected twin goals: punish the careless driver, and instill good driving habits in the general population.” -C. A. MacLennan Hemenway, David. Private Guns, Public Health
Public Health Model • Pre-injury: • Waiting periods • Restricted gun ownership • Injury phase: • High lethality ammunition • High capacity magazines • Automatic weapons • Post-injury phase: • Medical and law enforcement response • Violence intervention Public Health Paradigm: Injury reduction should focus on three temporal phases of injury (Haddon Matrix) Hemenway, David. Private Guns, Public Health
Public Health Model: Goals • Rigorous data proving relation of policy change and injury prevention • Physician leadership to advocate widespread policy change • Change in social norms • Spitting in public • Smoking Hemenway, David. Private Guns, Public Health
Public Health Model: Questions 1) Do very strict limitations on sale, storage, and carry of guns effect gun violence? 2) Does owning a gun make you more or less safe? 3) Do restrictions on carrying a concealed weapon affect gun violence? Data on violence and gun control is muddied by changes in gun violence influenced by other issues like crack cocaine and gangs, policy changes advocated by the gun lobby, and improved survival from better EMS and trauma care Hemenway, David. Private Guns, Public Health
The Test Tube: DCDo strict gun laws prevent deaths from gun violence? • 1976: DC instituted a handgun ban • Prohibited purchase, sale, transfer, or possession of handguns unless already licensed • Mandated all guns be stored disassembled and unloaded
The Test Tube: DCDo strict gun laws prevent deaths from gun violence? • 1991: Loftin et al • Before and After analysis of DC firearm homicides and suicides • Compared to violent injury in surrounding counties of MD and VA Effects of restrictive licensing of handguns on homicide and suicide in the District of Columbia.Loftin C, McDowall D, Wiersema B, Cottey TJ.N Engl J Med. 1991 Dec 5;325(23):1615-20.
The Test Tube: DCDo strict gun laws prevent deaths from gun violence? • 1991: Loftin et al • Suicides declined from 2.6/mo to 2.0/mo • Homicides declined from 13/mo to 9.7/mo • No significant change in adjacent areas • No significant change in non-gun related suicides or homicides Effects of restrictive licensing of handguns on homicide and suicide in the District of Columbia.Loftin C, McDowall D, Wiersema B, Cottey TJ.N Engl J Med. 1991 Dec 5;325(23):1615-20.
The Test Tube: DCDo strict gun laws prevent deaths from gun violence? • June 2008: DC vs Heller • Supreme Court overturned DCs gun law • Declaring it unconstitutional Effects of restrictive licensing of handguns on homicide and suicide in the District of Columbia.Loftin C, McDowall D, Wiersema B, Cottey TJ.N Engl J Med. 1991 Dec 5;325(23):1615-20.
The Risk of Gun OwnershipDoes owning a gun make you safer? • As of 2004 there were 9 case controlled studies examining the risks of owning a firearm. • RR of homicide is 2.2 to 2.7 • RR of suicide is 1.4 to 4.8 • Largest study of firearm use in Memphis, Seattle, and Galveston. A home firearm used for injury or defense was comparably: • 4-fold more likely to be involved in accidents • 7-fold more likely to be involved in assault/homicide • 11-fold more likely to be involved in suicide Cummins P and Koepsell TD Does Owning a Firearm Increase or Decrease the Risk of Death? JAMA 1998 280(5): 471-473 Kellerman et al. Injuries and deaths due to fireaarms in the home. Journal of Trauma 1998. 42:263-7.
Concealed Weapons PermitsDo CCW laws effect gun violence? • Types of Concealed Weapons Permit Laws: • Shall issue • Mandates that police grant a conceal weapons permit if the applicant meets minimal requirements • May issue (12 states) • Gives police discretion to grant or deny an application for concealed weapon permit • No permit required (Vermont) Since the 1990s there have been nationwide changes towards shall issue laws Hemenway D. National Attitudes Concerning Gun Carrying in the United States. Injury Prevention. 2001;7:282-285
Concealed Weapons PermitsDo CCW laws effect gun violence? There are many studies on the effects of concealed weapons laws, in a broad range of journals with inconsistent results Hemenway D. National Attitudes Concerning Gun Carrying in the United States. Injury Prevention. 2001;7:282-285
Concealed Weapons PermitsDo CCW laws effect gun violence? • “The Task Force's review of firearms laws found insufficient evidence to determine whether the laws reviewed reduce (or increase) specific violent outcomes. Much existing research suffers from problems with data, analytic methods, or both. Further high-quality research is required to establish the relationship between firearms laws and violent outcomes.” MMWR: First Reports Evaluating the Effectiveness of Strategies for Preventing Violence: Firearms LawsFindings from the Task Force on Community Preventive Services. Oct 3, 2003. Accessed at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5214a2.htm
Public Health Questions • 1) Do very strict limitations on sale, storage, and carry of guns effect gun violence? • Maybe, keep an eye on DC • 2) Does owning a gun make you more or less safe? • Less safe (from suicide, homicide, and gun accidents) • 3) Do restrictions on carrying a concealed weapon affect gun violence? • Unclear Hemenway, David. Private Guns, Public Health
National Opinion • The majority of Americans feel less safe as gun ownership in their communities increases. (59% felt less safe in a 1996 random dial telephone survey) • The majority of Americans do not feel citizens should be allowed to carry weapons in public places (88-94% in a 1999 random dial telephone survey) Hemenway D. National Attitudes Concerning Gun Carrying in the United States. Injury Prevention. 2001;7:282-285
Firearm Safety • There are no federal safety regulations for firearms • Gun Industry Resists • Drop tests • Trigger strength regulations • Magazine safeties which prevent guns from firing if the clip is out • Loaded chamber indicators This gun can still be fired!! Even with the clip out there may be a round in the chamber.
Firearm SafetyJunk Guns, Saturday Night Specials • Cheap domestically produced 9mms • Domestically produced guns are less tightly regulated • “Ring of Fire” • One third of handguns produced in the 1990s • Inaccurate • Unreliable • The gun lobby argues that regulating these gun would restrict the poor’s access to firearms and thus violate the second amendment and the equal protection clause
Firearm Storage • Organizations (from gun manufacturers to the AAP) suggest storing guns locked and unloaded • 21% of guns owners store guns loaded and unlocked • 12-14% of gun-owning households with children store guns loaded and unlocked Hemmenway et el. Firearm training and storage. Journal of the American Medical Association 1995. 273: 46-50 Hemenway, David. Private Guns, Public Health