From Calibre Press | calibrepress.com
[Our 2-part series on preparing for encounters with the media will continue next week.]
The following is a continuation of a series of excerpts from a book written by Dr. Martin Greenberg, an orthopedic surgeon who is also a police officer, SWAT operator and tactical medic. Dr. Greenberg’s mission is to give officers the information they need to understand and handle a wide variety of injuries that may be suffered during the course of police work.
His book is titled The Law Enforcement Medical Encyclopedia: Navigating Medical Challenges in a Dangerous World. Dr. Greenberg has agreed to share a few chapters in the interest of getting this information into as many officers’ hands as possible as quickly as possible. Over the next few months, we will intermittently share several chapters. [The first excerpt was published HERE.] If you would like to order the entire book—which we highly recommend—information on where you can get a copy will be included at the end of each excerpt.
The following comes from a chapter titled, A Brief Firearms Primer and Medical Ballistics.
SCENARIO
The tactical team is called out to a barricade where a sniper is on a shooting spree with a scoped rifle from an upper floor window of a building on a narrow urban street. Multiple victims are reported. EMS vehicles cannot respond as they are in the field of fire. The street is isolated. Negotiators arrive but cannot communicate with the suspect.
Tactical team members don their level IIIA tactical vests and helmets. They respond to the scene and stage at the command center around the blind B-C corner of the building. Marksmen take positions on rooftops surrounding the barricade but lack a clear view of the suspect because of the narrow street. The only building entry is on the A-B side in view of the sniper.
The team decides to deploy in their assault vehicle with level IV armor. Proceeding down the street with eleven officers in the vehicle and seven walking behind, they immediately take fire. Multiple rounds hit the vehicle without apparent effect. An officer behind the advancing bear is hit in the helmet and immediately goes down. The vehicle reverses and retrieves the injured officer. The vehicle then backs up to the front door and empties the eleven plus six team members into the building. Two teams then simultaneously clear the building. The apartment is reached and dynamically entered. The perpetrator is able to fire a handgun at the point officer, striking him in the center of his vest. Responding .223 caliber gunfire strikes the perpetrator’s torso center mass in her ballistic vest and immediately immobilizes her. The point officer suffers only a chest wall contusion from the handgun round.
INTRODUCTION
We are all familiar with the Texas clock tower massacre when on August 1, 1966, ex-military marksman and University of Texas student Charles Whitman wreaked havoc from an elevated position with a high-powered, scoped rifle killing fourteen people and wounding more than thirty. This episode is credited to be a motivating factor for developing the modern SWAT team concept.
Possibly readers have seen the movie Phone Booth (2002) where a sniper holds a hostage at bay from a distance. To understand the impressive level of destruction a single skilled rifleman can generate, we must understand the topic of ballistics. The American Heritage Dictionary defines ballistics as “The study of the firing, flight and effects of ammunition.” (1) The obvious questions our scenario raises and which we hope to clarify here include what is the difference between handgun and rifle rounds, what type of protection does soft or hard armor provide, what types of gunshot injuries are most serious and how should they be treated? We will also address the issue of how we can avoid becoming the victims of gunshot trauma.
NOMENCLATURE
A basic introduction to the various classes of handguns and long guns is needed to define the terms we will be using in the remainder of this discussion. Officers may already be familiar with this section of information.
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Editor’s note:
For this purpose, we have posted this section on a separate page for those interested in a thorough review of weapon and ammunition types and nomenclature.
CLICK HERE to go to that page.
You will be able to return to this main article from that page.
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BALLISTIC ENERGY TRANSFER
Ballistics is the study of bullets in motion. Subtopics include interior ballistics (bullet motion in firearms), exterior ballistics (bullet motion after leaving the barrel) and terminal ballistics (bullets’ effect upon targets). For our purposes, wound ballistics is the terminal ballistic study of living tissue.
Remembering high school physics, all objects in motion have kinetic energy that becomes potential energy as the object stops moving. The total kinetic energy of an object when moving equals its total potential energy at rest. A slowing object gives off its kinetic energy to its surroundings. A rapidly decelerating bullet dumps its kinetic energy rapidly into the object it strikes. The more kinetic energy that is almost instantly expended, the more energy the target must instantly absorb.
The amount of tissue damage imparted by a projectile is in part determined by its ability to transfer ballistic energy to living tissue exceeding that tissue’s ability to absorb it. Kinetic energy is defined by the formula: Kinetic Energy (K.E.) = 1/2 Mass (M) x Velocity (V) squared. This means that if the weight of the bullet doubles, so does the kinetic energy. If the projectile’s velocity doubles, its kinetic energy quadruples. Kinetic energy is most dependent upon the velocity of the projectile. Of course, the bullet must be able to come to rest within the target to impart all its kinetic energy.
Dr. Martin Fackler, the “father” of wound ballistics, feels that projectile velocity 2,000 ft. /sec. is the threshold for high energy level tissue destruction. He pioneered the use of the 10% ballistic gelatin medium as having similar penetration characteristics as living tissue. If a round passes through the target making a small hole and continues to travel through several sheetrock walls in an urban setting, a dangerous situation arises. Considering the width of a possibly heavily clothed human torso, about 12-18” of penetration seems ideal to achieve maximal safe energy transfer.
Depending upon the location of the entry wound and the path of the projectile within the body, different organs may be struck. The projectile’s effects will be directly related to the involved organ systems, their vascularity and anatomic characteristics (solid vs. hollow and liquid vs. air vs. bone consistency). The actual hole the bullet makes throughout its trajectory through the body is called the permanent wound channel. However, the projectile is actually pushing tissue away from it as it imparts its kinetic energy creating a temporary cavitation that has a lifetime of only 5-10 msec. The size of this temporary cavity and the effect of its accompanying shock wave on surrounding tissue vary with the amount of kinetic energy transferred and the local tissue’s elasticity and cohesiveness.
Low velocity rounds (most handgun rounds) lack the ability to expand tissue beyond its elastic limit. High velocity rounds (most centerfire rifle rounds) impart adequate energy to exceed local tissue’s elastic limit and cause the tissue to “explode” or shatter. This is one reason for the explosive effects caused by high velocity limited penetration ammunition. Dramatic local occurrences when centerfire rifle rounds enter tissue include tail splash where tissue is violently driven backwards, the formation of a temporary cavity up to thirty times the diameter of the permanent cavity, undulating local pressures of up to 200 atmospheres (atm.) and the sucking into the wound of foreign matter and damage to distant vital structures including blood vessels, nerves, and even bones.
Density and elastic cohesiveness of involved organs are other important wounding factors. (4) For example, DeMaio states that muscle and liver have about the same density. Liver, however, has much less elasticity or cohesiveness than muscle. A projectile traversing muscle will usually leave only a permanent wound channel while one traversing liver will create an explosive effect similar to shooting a gallon plastic water jug. Lung being highly elastic may sustain only little damage by a traversing projectile. Minimum critical velocities of 2,625 to 2,953 ft. /sec. are associated with supersonic wound shock waves and the large temporary cavities noted above. Each bodily tissue may have a unique level of kinetic energy needed to exceed its elastic limit creating explosive effects.
Bullet factors also affect the loss of kinetic energy. Yaw, or “the deviation of the bullet from its line of flight” (5) will increase the amount of tissue contact with the projectile and cause tumbling within the target. The high velocity bullet may also fragment in predictable ways as tumbling deceleration strains the bullet to its failure point and increasing the energy dump and wounding effects through multiple projectile paths. The caliber, shape, and construction (jacketed, semi-jacketed, or lead projectile) will also play a role. The critical speed for hollow-point expansion varies but starts at about 705ft. sec. (5) Shotgun rounds create high velocity wounds as the multiple pellets and packing from any gauge shot shell create a contaminated wound requiring debridement. In the most common shot shell, 00 (double 0) buck pellets each measure 32 caliber. Shot patterns generally disperse 1”/ft. of travel from the muzzle. More pellets on target mean more wounding effects. As a twelve-gauge round will have eight to twelve of these pellets, imagine being shot with eight to twelve “00” .32 caliber bullets simultaneously! Shotgun slugs (twelve-gauge = seventy caliber) create a low velocity injury pattern.
ENTRY AND EXIT WOUNDS
Gunshot wounds may be penetrating or perforating. Perforating wounds exit the target. In contact wounds, the muzzle of the weapon is in hard or soft contact with the skin. In hard contact wounds, the skin under the muzzle is tattooed. In soft contact wounds, gas escapes around the muzzle creating a ring of removable soot. Angled contact wounds have an oval configuration and a radial, fan shaped, soot pattern on the side opposite to the muzzle. The radial soot is temporary as in light contact wounds.
Incomplete contact wounds occur when the muzzle is in incomplete contact with the skin. Gases and soot then escape radially through the muzzle/skin gap. Microscopic elements from all parts of the cartridge are found within the permanent channel. Near contact wounds occur when the muzzle is close to the skin. They have a baked-in, tattooed appearance with a temporary surrounding soot ring that may be radial if the trajectory is angled. Here, the radial soot-ring points towards the muzzle. This is the case when the muzzle/skin gap exceeds 10 mm. (6)
Angled light contact wounds may be differentiated from angled near contact wounds as the latter has a tattooed component. This is an important forensic distinction in discovering the direction from which a bullet was fired. Intermediate range wounds exhibit the classic powder tattooing pattern. This pattern begins at about a 10 mm muzzle/skin gap. There is therefore a continuum of overlapping wound patterns from hard contact to intermediate types. The density and distribution of tattooing depend upon many factors including the angle of trajectory, the quality of the target skin and overlying clothing.
In angled shots, the tattooing is denser on the “muzzle side” of the wound. Tattooing is colored red, orange, or brown and is an ante-mortem (before death) finding. These are punctate abrasions, not burns, and their color is due to the body’s reaction of bruising or bleeding.
Shooting dead people at an intermediate range causes a gray or yellow powder tattoo. Tattooing is permanent and does not occur on palms or soles. The term “powder burn” refers back to black powder wounds where the deposited powder actually burned the skin setting overlying clothing ablaze!
Neither powder tattooing nor soot deposition will occur beyond a muzzle/skin gap of about 30 cm. With distant wounds, only the mechanical action of the bullet on the skin will occur. Entry wounds are characterized by a red abrasion ring surrounding the bullet hole. A fresh abrasion ring appears moist and granular. Eccentric abrasion rings do not describe a bullet’s trajectory. Exit wounds at any distance generally appear larger and more irregular than entry wounds. They lack an abrasion ring. The deformation and tumbling of a non-stabilized projectile in the body explains the irregular shape of the exit wound. Abraded exit wound margins may rarely occur when the exit skin is braced or “shored” against a surface such as sitting in a chair or lying on the floor. The bullet’s shape also does not correlate with the size of the exit wound.
“ONE SHOT STOPS”
The search for the “magic” handgun round that will produce instant incapacitation has been the subject of great debate over the last twenty years. Clint Smith, a nationally celebrated firearms trainer and the director of Thunder Ranch in Lakeview, Oregon, put the entire debate into focus by stating, “The purpose of a handgun is to fight your way back to your long gun.” Handguns are convenient and portable but may not always be effective man-stoppers. In 1992, Evan Marshall and Benton County, Indiana Sheriff’s Department Cpl. Ed Sanow published Handgun Stopping Power. (7) Here, they assembled a large number of actual, well documented shootings organized by handgun load and determined what percentage occurred through “one shot stops.” The actual mechanism of the stop or its fatality was not documented.
The “best of class” for each caliber revealed: one shot stops
.380 ACP-Federal 90-gr. JHP — 65%
.38 Special (2” barrel)-W-W 158-gr. LHP+P — 67%
.38 Special (4” barrel)-W-W 158-gr. LHP+P — 75%
Federal 9mm. 115-gr. JHP+P+ — 89%
.357 Magnum-Federal 125-gr. JHP — 97%
.44 Special-Federal 200-gr. LHP — 72%
.44 Magnum-W-W 210-gr. STHP — 89%
.45 ACP- Federal 230-gr. Hydra-Shok — 91%
Steve Fuller created a computer program with this data dubbed “the Fuller Index.” He predicted that a round with a kinetic energy of around 650 ft./lbs. could be expected to produce a one shot stop. However, since that time, it has been well determined that the most common reaction to being shot barring a significant neurovascular injury is no reaction. In the old west, a famous saying was “havin’ your ten.” This means that even after sustaining a mortal vascular injury an accomplished pistolero would have about ten seconds to return fire. Another well-known Clint Smith quote explaining this was, “Just because you got to shoot doesn’t mean you won. It just means you had your turn.”
BALLISTIC GUNSHOT WOUND PROTECTION
“Ballistic body armor is designed to defeat projectiles in motion.” (8) The National Institute of Justice (N.I.J.) has defined ballistic vest threat levels designed to defeat specific rounds. Soft body armor is made from polyethylene fiber (Spectra made by Allied Signal Company), Aramids (Kevlar made by DuPont, and Twaron made by Azko-Nobel). Soft body armor is basically a ballistic resistant fabric available as concealable or tactical armor.
The following threat protection levels are available for soft armor:
Threat level IIA must defeat a 9 mm full metal jacketed Remington (9mm FMJ Rem) fired from a 4” barrel traveling at 1,090 ft./sec. and a .357 Mag. 158 gr. semi-jacketed soft point Remington (.357 SJSP Rem) fired from a 4” barrel traveling at 1,250 ft./sec. Other non-mandated rounds this threat level stops include most non-FMJ 9 mm rounds, the .45 ACP, several .44 Magnum rounds and 12G 00 buckshot.
Threat level II stops the mandated 9 mm 124gr. FMJ Rem fired from a 5” barrel traveling at 1,175 ft./sec. and the .357 Magnum 158gr. SJSP Rem fired from a 6” barrel traveling at 1,395 ft./sec. (note increased velocity when a round is fired from a longer barreled weapon). Non-mandated rounds include 12G shotgun slugs, a variety of 9 mm FMJ rounds, and even the .50 Action Express round.
Threat level IIIA stops the mandated 9 mm 124gr. FMJ Rem fired from a 16” barreled carbine traveling at 1,400 ft./sec. and the .44 Magnum 240gr. SWC Rem fired from a 6” barrel at 1,400 ft./sec. Hard armor inserts usually made of steel, ceramics, aluminum or titanium are available for added frontal torso protection for this soft armor. More exotic armor plating in silicon carbide, boron carbide or cermets (ceramic/ metallic combinations) also exist.
Hard armor is available as a threat level III and protects against centerfire rifle rounds 5.56 x 45mm (.223) and 7.62 x 51mm (.308). It is also available in level IV protecting against the 30.06 AP (armor piercing) round.
Fragmentation armor (FLAK Jacket) protects against shrapnel injury but possesses no official ballistic rating. Puncture resistant vests are designed to defeat only edged weapons.
Reviewing Second Chance compiled statistics makes the obvious case for wearing a ballistic vest. FBI stats show that the odds of surviving a shootout are fourteen times higher if body armor is worn. These data also show that between 1980-1996, 42% of the 403 officers killed with firearms could have been saved were they wearing body armor. 88% of all law enforcement officers were shot with bullets that would have been defeated by soft armor.
CENTRAL NERVOUS SYSTEM (CNS) INCAPACITATION
Injuring vascular (blood containing) organs such as the heart and liver or disrupting major blood vessels such as the femoral or carotid arteries will result in major blood loss and rapid incapacitation within ten to fifteen seconds because of hypovolemic (blood loss) shock. (9) A low or high velocity gunshot injury to the Central Nervous System (CNS) above the shoulder blades, in the brain stem or within the cranial vault when properly placed may result in instant incapacitation.
The frontal T-shaped area describes the eyes and nose and is currently called “the T box.” The rule of thumb for CNS incapacitation is “the higher on the spine the better…the subject goes down precipitously as if you’d flicked a light switch.” (10) This describes neurogenic (nervous system) shock and is the goal of the precision marksman. To achieve this result, the brain stem at the pons, medulla oblongata or upper cervical spine level must be severed or the cranial vault must be breached preferably by a high velocity round.
The landmark for the medulla is in the “moustache” area just below the middle of the nostrils (nares) on the frontal view of the face. The landmark for the back side of the head is less distinct. It is a line drawn between the lower earlobes (tragus) in the midline of the head. A low velocity round may also be effective within the cranial vault but striking the frontal cortical motor strip assures the desired result. The landmark for this structure is located starting above the top of the ear (pinna) and extending toward the top of the head on its side view. Major John Plaster (Special Operations Group, ret.) likens this lateral area as similar to the area covered by wearing headphones.
Only the upper one-third of the head contains the cranial vault and brain. The liquid density of the brain accurately reproduces the effects of shooting a gallon water jug and transmits the temporary cavitation shock wave very well. This area is about four to five inches high and six inches wide.
Intracranial gunshot wounds comprise one-third of all fatal shootings. (11) The entry wound punches out a relatively round skull fracture that drives bone fragments into the brain. High or even low velocity rounds may create shock waves causing secondary skull fractures. Intracranial bullets may ricochet 10% to 25% of the time within the cranial vault, also creating fractures and/or more brain parenchymal (tissue) damage. Increased intracranial pressure because of bleeding or swelling may be a partial explanation for the devastating nature of these wounds.
DeMaio states that 40% of fatal civilian gunshot wounds involve the head (50% involve the heart and great vessels while 10% are miscellaneous). Bullets may follow the inner curvature of the cranial vault before coming to rest. A skull x-ray is always a good idea to document bony injury.
The author has had personal experience with a head wound where midline anteroposterior entry and exit wounds were present in a lucid victim with no skull fracture demonstrating the tendency of bullets to track along the bones of the skull. The size of the permanent cavity within brain tissue bears no resemblance to the caliber or kinetic energy of the round. The time needed for “instant incapacitation” may be calculated, per Plaster, to be approximately .12 seconds for a .308 round to travel 100 yards from the weapon to the subject and another ½ millionth second to divide the brain stem.
The realistic marksmanship ability to accomplish these shots is a relevant question. If an acceptable level of marksmanship accuracy is one Minute of Angle (M.O.A.) or one inch off target/100 yards, it would be impossible to make the cranial vault shot beyond about 300-400 yards. As most tactical scenarios occur within seventy-five yards, this shot may be a realistic goal. The ability to successfully make a brain stem shot is more questionable. As the angle of elevation increases, the trajectory may miss the medulla with an elevation angle of only five degrees although the pons (lower brainstem) and upper spinal cord could still be struck successfully if the shot remains midline.
GUNSHOT WOUND MEDICAL CARE
Despite the foregoing analysis, do not despair. Actually, only about 10% of gunshot wounds are fatal. Gunshot victims should be reassured they won’t die. It is important to avoid the pessimistic mindset that you will die if shot if for no other reason than if you stop fighting you really may die. If injured, don’t be sad-get mad! No one should be allowed to take you from your family and loved ones! If you make it to a Trauma Center, you have a 98% chance of survival.
The first priority in providing medical care to the civilian or law enforcement gunshot victims is to search and completely disarm them. For officers this includes all primary, secondary, and backup firearms. The weapon search includes edged weapons. Do you know where your co-workers secrete all their weapons? An injured, disoriented team member may think he is being attacked by the treating teammate and respond violently. If they are not disarmed, further unnecessary injury may result.
The victim should be evacuated to a safe location for care if possible. The bare minimum care in the inner perimeter should be provided including a quick A, B, C (Airway, Breathing, Circulation) first aid evaluation. A wound dressing may be applied as needed. An ambulatory victim may walk to safety. A non-ambulatory victim may be carried into a safe area via a carry technique or a litter. The staging of appropriate medical care should conform to the Tactical Combat Casualty Care (TCCC) guidelines. That algorithm is beyond the scope of this discussion. However, all armed individuals would be well advised to have a tourniquet on their person to control significant extremity bleeding. Arms and legs can well tolerate up to two hours of tourniquet use. Approved tourniquets, if possible, should be strictly monitored by the person who applied them. Documentation of tourniquet application time must accompany the victim. Extremity wound care may also include the application of a compression dressing and the use of hemostatic agents. Remember, the survival rate after sustaining a gunshot wound is 90%!
The Law Enforcement Medical Encyclopedia: Navigating Medical Challenges in a Dangerous World is available directly from the publisher, Dorrance Publishing Company, by clicking here or calling (800) 788-7654. It’s also available on Amazon here.
REFERENCES
1 American Heritage Dictionary, third ed. Houghton Mifflin, USA p.141
2 DeMaio, Vincent-Gunshot Wounds, CRC Press, Boca Raton, 1993 p 12 (See addendum excerpt reference above)
3 Butler, D.F.-United States Firearms: The First Century 1776-1875. Winchester Press, New York 1971(See addendum excerpt reference above)
4 ibid. DeMaio, p. 43
5 ibid. DeMaio, p.46
6 Bruchey, W.J. et al., Police Handgun Ammunition, US Gov’t. Printing Office, 1984
7 Op. Cit. DeMaio, p.57
8 Marshal, E. and Sanow, E.-Handgun Stopping Power, Paladin Press, Boulder Colorado 1992
9 Second Chance Live Fire Demonstration Notes presented by Lt. A. Kulovitz (Cook County Sheriff’s Police, retired)
10 Plaster, J.-The Ultimate Sniper, Paladin Press Boulder, Colorado 1993 p.131
11 ibid. Plaster, p.131
