Psychological and
Physiological Realities of
Deadly Force
Confrontations
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Topics of Discussion
• Introduction
• Dynamics of Deadly Force Confrontations
• U.S. Legal Standards and Court Decisions
• Practical Considerations for Drafting of Rules
for the Use of Force (RUF) and/or Rules of
Engagement (ROE)
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Basics Concerning Deadly
Force Confrontations
• Combat is the Universal Human Phobia
• Human Beings have a natural aversion to
inflicting physical violence on members of
their own species
• Each deadly force confrontation is unique and
involves a wide variety of subjective variables
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What Is Deadly Force?
• That force reasonably likely to result in death
or seriously bodily injury to:
– Life
– Limb
– Eyesight
The firing of a weapon is by definition
the exercise of deadly force
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Human Nervous System
• Central Nervous System
– Brain and Spinal Cord
• Peripheral Nervous System
– Somatic Nervous System – Conscious
– Autonomic Nervous System – Unconscious
• Sympathetic
• Parasympathetic
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Dynamics of Deadly Force
Confrontations
• Tache-Psyche
• Action v. Reaction
• Wound Ballistics
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Tache-Psyche Effect
• During a deadly force confrontation, the autonomic
nervous system is in control
• The body automatically allocates resources to
enhance chances of survival
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Fight or Flight
• Physical: Adrenaline
dump
– heart rate increased, blood
flow increased to major
muscle groups
• Mental: Midbrain in control
– Part of brain which has same
structure and function as
animal brain
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Sensory Distortion
• Sight
– Loss of near vision and depth perception
– Loss of peripheral vision, i.e., “tunnel vision”
– Heightened visual acuity
• Hearing
– Auditory exclusion
– Heightened auditory acuity
• Touch
– Tactile sense deteriorates
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Cognitive/Thought Distortion
• Disjunction of time/space continuum
• Automatic behavior
• Memory loss or gaps
• Intrusive thoughts/Dissociation
• Temporary Paralysis
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Effects of Hormonal Induced Heart Rate Increases
CONDITION BLACK
175 beats per minute:
thought processing
deteriorates, sensory
distortion
CONDITION YELLOW
115 beats per
minute: fine
motor skill
deteriorates
80
140
220
200
180
CONDITION RED
160 155 beats per minute:
complex motor skill
deteriorates
120
100
CONDITION WHITE
60-80 beats per minute:
resting heart rate
Implications
• There is no way to predetermine what sensory
or cognitive distortion an individual will
experience
• The body will focus on certain targets to the
exclusion of others
• The body is effectively operating on autopilot. Training - good or bad - will take over
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Deputy Sheriff Dinkheller
Shooting
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Action v. Reaction
• Bad guy decisions – When
• Good guy decisions – Three steps
– Decision Time: Perceive threat and decide
on appropriate course of action
– Response Time: Send nerve signals to
relevant muscle group
– Mechanical Time: Physically complete
action, i.e., trigger breaks, hammer falls,
firing pin is struck, firing pins strikes
primer, etc.
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Action v. Reaction
• Under ideal conditions, reaction time is anywhere
from 0.8 – 1.5 seconds
• Reaction time is further affected by:
–
–
–
–
–
Sudden, unexpected movements
Rapid and unpredictable movement of shooter and targets
Limited target opportunities
Low light or partially obstructed
Stress of sudden close, and personal violence
• “Tueller” Drills – 21 foot/6.5 meter rule
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Jewelry Store Police Killing
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Wound Ballistics
Physical Factors
• Penetration
• Permanent Wound Cavity
• Temporary Cavity
• Fragmentation
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Wound Ballistics
Rifle v. Pistol
• Pistol Bullets
– Relatively slow impact velocities = no reliable fragmentation
– Only means of incapacitation are tissue “crush” and
penetration into vital organs
• Rifle Bullets
– Impact velocities high enough to
result in fragmentation
• Bigger holes better than smaller, deeper holes better
than shallower, more holes better than fewer
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Wound Ballistics
Psychological Factors
• Expectations
– Security guard in bank robbery
– Police officer in drug raid
• Will to Fight
– FBI Shootout in Miami
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Wound Ballistics
Common Myths
• Heart shot will immediately
incapacitate
• Sensory effects of bullet
wounds are immediate
• “Knock-down” power of small
arms
• “Center mass” shots always hit
vital organs
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Trooper Coates Shooting
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U.S. Legal Standards
• Domestic use of deadly force is analyzed
under 4th Amendment of the Constitution
– Objective Reasonableness Standard
• Court Decisions
– Graham v. Connor (1989)
• Reasonableness judged from perspective of law
enforcement officer, not with “20/20” Hindsight
– Brown v. United States (1921)
• Detached reflection not required in the presence of an
uplifted knife
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Deadly Force Standard for U.S.
Military Personnel
• Standing Rules for the Use of
Force
– Inherent right of self-defense
– Deadly force is to be used only
when all lesser means have failed
or cannot reasonably be employed
– Reasonable belief that person
poses risk of death or serious
bodily harm
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Deadly Force Standard for Federal
Law Enforcement Personnel
• Law enforcement agents/officers of the Department
of Justice may use deadly force only when
necessary, that is, when the officer has a reasonable
belief that the subject of such force poses an
imminent danger of death or serious physical injury
to the officer or to another person
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RUF/ROE Practical
Considerations
• What is serious bodily injury or
death?
• Minimum force/minimum number
of shots
• Limitations on when weapon may
be loaded/round in chamber
• Tache-Psyche & Investigations
• Body armor and risk
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Warning Requirement???
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RUF/ROE Potential Problems
• Fear of using force/fear of
weapons
• Qualification versus training
mentality
• Misunderstanding of rules
governing use of deadly
force
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RUF/ROE Potential Problems
• Misunderstanding the tactical dynamics of a
deadly force encounter
• Unclear command guidance
• “Accidental” discharge paranoia
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Consequences of Poorly Drafted
or Misunderstood RUF/ROE
• Afghan robbers with AK-47 not threat!
• Green-zone Entry Control Point Guards
• Marines at Fallujah
• 82nd Airborne Division troops in Kosovo
• Sentry spotting insurgents setting bomb
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Conclusion
• Deadly force confrontations involve rapidly changing,
dynamic, and unique circumstances
• The realities of Tache-Psyche, Action v. Reaction, and
Wound Ballistics are present in all deadly force
scenarios
• Effective RUF/ROE will be drafted with an
understanding of these realties
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