Rarely, there is a self defense shooting where the assailant
presents with entrance wounds in the back, yet the defender is
certain that he or she used force justifiably to stop a real threat
to the defender's life. How can this be explained, and how may
it be demonstrated to a jury if needed?
This scenario is better documented in law enforcement shootings, but
is far from unknown in non-law enforcement defensive shootings.
In 2016 I was engaged as an expert in a criminal case in which a
homeowner (let’s call him Smith) was charged with homicide for
having shot an intruder (let’s call him Jones) in Smith's
home. It was my job to explain to the jury how the homeowner
could have been justified in the use of lethal force when the
intruder died (offsite) from a bullet that made an entrance wound in
the intruder’s back.
The short version of my reconstruction of the incident is that the
armed homeowner knew there was an intruder in the house who had made
a forcible entry (indication of criminal intent with potential for
violence). The armed homeowner entered his home, searched for
the intruder, and encountered the intruder at a distance of about
ten feet upon stepping into the doorway of a room in the
house. The intruder made a sudden move that the homeowner
interpreted as an assault, but which was the beginning of a spin
towards a large window that the intruder had opened as an escape
route. When the intruder made the sudden move, the homeowner
discharged a round from his 9mm pistol, a round that connected with
the intruder as he spun away from the encounter. The intruder
died nearby from a bullet wound that had entered the intruder's
The homeowner was charged with homicide and claimed self defense.
How could I explain to uninformed members of the jury and to the
court, with serious credibility, that Smith could have used lethal
force correctly, even though the fatal entrance wound was in the
Jones’s back? At that point the intruder was apparently trying
to escape and no longer threatening the homeowner with serious
bodily injury or loss of life, the usual criteria in law for use of
lethal force in self-defense. For a vivid demonstration for
the jury, I had to actually test this scenario, with appropriate
timing, with live ammunition, at a shooting range. I had to
video and document the tests for my expert report in this case and
in preparation for my testimony before Smith's jury.
What follows is extracted from my expert report, albeit with the
names changed for privacy reasons.
As an expert and as a very interested person, one of the information
sources I attend to is the Force Science Institute (FSI) and the
Force Science Research Center located at Mankato State College in
Mankato, Minnesota. I read and collect the regular and
informative FSI newsletters. The FSI has done groundbreaking
research, mostly in a law enforcement context, about use of force
issues. One aspect of use of force that FSI has researched is
the timing of an encounter that justifies a response of lethal
force. Some aspects about the mechanics and human physiology
of that combination have long been known. Some remained to be
discovered or demonstrated through testing by FSI.
We've long known that there is some time lag between an external
stimulus to human action, and the resulting action itself.
Although the timing can be different with an audible stimulus and a
visible stimulus, let us discuss a visual stimulus. For a
person to respond to a visual stimulus, several serial (sequential)
things must happen.
First, the person must look at and see the visual environment.
That is, the person must see whatever the stimulus may be and that
visual image must be registered by the photoreceptor cells of the
retina, transmitted to the optic nerve, and transported to the
brain. That happens quickly, but it does take time.
Let's suppose that the test stimulus is a light changing from green
to red, and let’s identify the time it takes to get that image to
the brain as the "apprehension time."
Then, the brain must interpret the image. That is, the brain
must figure out "Hey, there was a green light shining but it went
out and now there's a red light shining." That happens
quickly, but it also takes time. We might call this the
Next, the brain must figure out what the information means and
decide what to do with the information. It could take days or
weeks before any decision is made about what to do with visually
received information (e.g., responding to a letter). Or, there
could be an urgent, pre-planned response, such as "Send a signal to
the leg to stomp the foot on a simulated brake pedal." Still,
an analysis must be conducted about what to do with the information,
and a decision must be made before any response is possible.
No matter how well pre-planned, this process also takes time.
It takes longer with an unanticipated stimulus. Let's call
this the "decision-making time."
Then, the brain must send the signal out to the parts of the body
necessary to carry out any instructions from the brain in response
to the initial stimulus. And, the nervous system must carry
the impulses to the correct parts of the body for action. For
example, maybe the brain must send a coordinated instruction to all
the muscles of the right leg and right foot for the foot to lift,
move over, and stomp down on a simulated brake pedal. It will
take time to formulate and send that complex set of signals, and for
the signals to travel to the necessary body parts. Call this
the "instruction time."
Finally, the necessary body parts must get into action and actually
follow out the instructions sent out over the neural links by the
brain. Of course, that takes time too. Call this the "
Each of these steps can usually be completed in a fraction of a
second, but these fractions necessarily add up. Adding up the
apprehension time, the interpretation time, the decision-making
time, the instruction time, and the performance time cannot be
eliminated, although with training and practice it can be
reduced. People with decent vision and reflexes will usually
take most of a second to complete this process, at best. When
we're young, we will be quicker. As we age, this process takes
more time. All of this has been studied and measured.
It has also been measured exactly how long it takes a bad guy to
snatch a concealed firearm from a waistband and fire a fatal shot.
The law enforcement world has long said, "Action beats
reaction." That is a recognition that the amount of time it
takes a bad guy to snatch and fire a gun is less time (quicker) than
the time it takes an officer to recognize the evolving threat and
It was the FSI that first put all of this together scientifically
and documented what experienced officers already knew, but
documented in valid experiments conducted by professionals and
published in peer-reviewed papers in professional publications.
What FSI learned and documented is that, if an officer is faced with
a potentially hostile bad guy and the bad guy makes a sudden move (a
"furtive move"), the officer dares not wait to see what might evolve
out of the move. If the officer waits until he sees a gun
emerge from the bad guy's waistband, the officer is likely
dead. It's simply too late at that point for the officer to
draw his own gun and fire before being seriously wounded by the bad
That's why a smart police officer may already have drawn his
firearm. That's why a smart police officer will instruct the
suspect to "move VERY SLOWLY." That's why a surviving police
officer will take cover if possible and fire his pistol if he sees a
FSI also documented another phenomenon known by experienced cops but
difficult to explain, also a timing issue. Not only can a bad
guy snatch a gun and kill an unprepared officer before the officer
can respond, but the same bad guy can also spin 180 degrees just as
quickly. Here's where understanding the timing becomes
Imagine this. Imagine a police officer (or a non-police
defender) is confronting a bad guy. Sensibly, the cop has his
gun drawn, pointing at the bad guy. The cop issues the command
to "Freeze!" Upon that command, the bad guy makes a sudden and
violent movement. In order to live to go home to his family,
the cop makes the immediate decision that the movement could be a
physical assault to capture the officer's gun, or it could be the
bad guy snatching his own gun. After a one-third or one-half
second of processing, the cop's brain dispatches the signal down his
neural pathways to his trigger finger telling his finger to contract
on the trigger of his pistol.
This signal is just racing past the cop's elbow when the visual
images coming into the cop's brain begin to suggest that the bad guy
is not actually attacking, but is in the process of spinning around,
maybe to escape. About the time that the signal to fire passes
the cop's wrist, his brain gets around to sending a follow-up signal
to the trigger finger to NOT contract. This signal to NOT fire
must follow the same pathway as the signal TO fire just did, at the
same speed. By the time the message to NOT fire is clearing
past the brain stem at the base of the brain, the signal TO fire
clears the knuckles and is contracting the muscles of the trigger
finger. When the officer's firearm discharges, the signal to
NOT fire is still somewhere near the officer's shoulder, flashing
its way to intercept the trigger finger contraction.
While this is going on, the bad guy has spun 180 degrees, and the
officer's bullet enters the bad guy's back. This has happened
many times. Finally, FSI brought the science of human
neurophysiology to the issue to explain how this can happen, and
The reader is referred to:
AN EXAMINATION OF POLICE OFFICER MENTAL CHRONOMETRY: “I
SWEAR...I DON’T KNOW HOW I SHOT HIM IN THE BACK”, by Jeffrey B.
Bumgarner, Ph.D., Texas Christian University, William J. Lewinski,
Ph.D., Minnesota State University, William Hudson, Ph.D., Minnesota
State University, Sgt. Craig Sapp, Tempe Police Department, done for
the Journal of The Association for Crime Scene Reconstruction, 2006
So, is there an explanation for how in the Smith incident the
entrance wound in Jones could be in the back, but Smith could still
have used lethal force in an allowable manner? Yes.
Imagine this. Both actors in this drama were psychologically
jacked up and totally on edge. Both were probably pumped full
Jones knew he was engaged in criminal activity, activity for which
there would be a high price to pay if he were caught. He was a
burglar. It is likely that he saw and/or heard Smith drive up
and get out of his vehicle. He may have seen that Smith was
armed. When Smith entered the house through Jones's point of
forcible entry (front door), he inadvertently blocked Jones's
primary escape route. According to Smith, he observed Jones
try to get to the back door in the kitchen, but when Smith issued
the verbal command to "Stop," Jones bolted instead. Now Jones
was trapped, and he knew he was. By that point, Jones was in
overdrive and red-lined. It has been learned since that Jones
swore that he would never go back to prison. With the
knowledge that Smith was armed, that put Jones in a literal
life-and-death situation, on life-and-death overdrive.
Smith entered his home knowing that some person was inside
committing a felony-level crime. The strange car was still
outside and the front door was kicked in. In the kitchen,
Smith had his first encounter with Jones. Jones was larger,
stronger, younger, and probably faster than Smith. Smith would
have known that, if it came to unarmed combat, Jones would have a
considerable advantage, a serious disparity of force. Also,
for practical and proper tactical reasons, Smith must assume that
Jones would in no way limit his criminality to felony
burglary. Rather, to be tactically sound, Smith must assume
that Jones would be willing to maim or kill in order to avoid
interdiction or capture. Plus, Jones had articulated to Smith,
"I'm going to hurt you." So, Smith was also ramped up
psychologically, also in overdrive.
It was while both were in this absolutely hyper state that they had
their final confrontation at a distance of about two or three
yards. Jones came into Smith's view because Smith moved into a
position where he could see Jones, not because Jones moved into
Smith's view. The layout of the house dictates this.
In this totally hyper state for both, Smith moves into a position
where Jones is visible. For a fraction of a second, both
freeze. At that point, Jones makes a sudden move.
Smith's brain registers that sudden movement and his brain
interprets it as "I'm being attacked," an essential and tactically
correct decision if he wants to survive. Smith's brain sends
the signal to his arms and hands to raise his pistol and squeeze the
That signal is racing down Smith's neural pathways. As with
the example above, the signal to raise the pistol and fire is just
passing Smith's elbow when his eyes and optic nerve begin getting
information to his brain that Jones may not be attacking, but may be
spinning around. About the time the signal to fire the pistol
is passing Smith's wrist, his brain sends out a follow-up message to
the hands and finger to NOT shoot. But, it's just too late for
that second signal to catch up with the first. The first shoot
signal gets to Smith's hand and the pistol fires. At this
point Jones has spun nearly 180 degrees and the bullet enters
So, was Smith justified in applying lethal force? Yes.
At the moment the decision to fire was made and the message was sent
by the brain, Smith was in fear for his life from a known criminal,
younger, larger, and stronger, who was trapped with no obvious route
of escape and desperate to avoid capture.
It is not Smith's fault that Jones triggered Smith's decision with a
sudden movement. That was Jones's mistake. It is not
Smith's fault that Jones's sudden move turned out to be the
beginning of a spin and not an attack. That sudden move was
Jones's mistake. And, it is not Smith's fault that Jones could
turn faster than Smith could send the recall signal. That is
just human neurophysiology, as has been demonstrated scientifically.
A known phenomenon
This phenomenon of timing with a quickly turning assailant is a well
known subject in the world of those who specialize in self defense,
including self defense instructors, self defense experts, and self
defense attorneys. However, it is not generally known among
the public, and often not known among police officers and
In the book, Deadly Force: Understanding Your Right to Self
Defense (Gun Digest Books, 2014), by Massad Ayoob and Jeff
Weiner, in the chapter "Shot in the back" the authors say:
This turning and shooting factor was later quantified in
peer-reviewed literature by Dr. Bill Lewinski, head of the Force
Science Institute, and still later rediscovered and quantified by
Dr. Martin Fackler and one of his associates at the International
Wound Ballistics Association, in the 1990s. I documented it
on film in 2001 for the ALI-ABA in a CLE (Continuing Legal
Education for attorneys) training film on management of deadly
force cases. ALI is the American Law Institute, the "blue
chip provider" of CLE training material, and the ABA is the
American Bar Association. It remains in the archives of
ALI-ABA in their CLE-TV series. It was documented on film
again in 2012, including live fire demonstrations on turning
targets, for "Personal Defense TV" on the Sportsman Channel,
available in their archives as well.
AN EXAMINATION OF POLICE OFFICER MENTAL CHRONOMETRY: “I
SWEAR...I DON’T KNOW HOW I SHOT HIM IN THE BACK”, by Jeffrey B.
Bumgarner, Ph.D., Texas Christian University, William J. Lewinski,
Ph.D., Minnesota State University, William Hudson, Ph.D.,
Minnesota State University, Sgt. Craig Sapp, Tempe Police
Department, done for the Journal of The Association for Crime
Scene Reconstruction, 2006, (See Appendix for full article).
This article reports the findings of a 4-experiment study
involving 102 police officers in a major police department in the
Southwestern United States. The results of the study
demonstrate that many variables go into an officer’s ability to
react to stimuli in a timely manner and that even in laboratory
conditions, there is ample time for the threat picture to change
before an officer can either turn on, or turn off, a decision to
react by firing a weapon.
Tobin and Fackler (20) conducted a study which measured the
reaction times of officers in firing drawn sidearms (but with
finger outside of trigger guard as per the standard police
practice) in response to stimuli, and compared those measurements
with the time it takes for a person to turn their torsos away (90
and 180 degrees) from officers after posing a threat. ... They
found that the average individual can turn his or her torso 90
degrees in 0.31 seconds and 180 degrees in 0.676 seconds. In other
words, in the time it took an officer with a drawn firearm to fire
his or her weapon at a threat, the suspect could already have
turned 180 degrees away from the officer at the moment of
A corollary to the plain implications of the time measurements is
the difficulty an officer (or any human being) has in “turning
off” a reactionary decision made in the moment. In a shooting
situation, once an officer decides to shoot at a suspect in
response to some threatening stimulus, it is nearly impossible to
abort that decision
In fact, the physical and psychological limitations of the human
condition do not apply only to law enforcement officers.
Detectives called to the scene of a “routine” shooting incident
between two civilians may wish to not-so-readily dismiss the claim
of the suspect that the victim had posed a threat, despite entry
bullet wounds in the victim’s back. Obviously, consideration of
reaction time doesn’t explain all shootings. Common sense,
eye-witness testimony, and physical evidence tend to close the
cases. But in those instances when common sense suggests the
suspect’s innocence while the victim’s wounds suggest the
suspect’s guilt, innocence may still be an option. (Emphasis
Testing the phenomenon
I determined to test this phenomenon for myself. A piece of
shooting range equipment I manufacture causes a target to rotate
through 180 degrees. I mounted a 3D mannequin target on one of
my units, and dressed the dummy in a clean T-Shirt.
3D mannequin target mounted on turning operator
I took a video of this unit, at 30 frames per second, rotating the
target so I could play it back one frame at a time, count the frames
from beginning of the turn to end of the turn, and thereby get an
accurate time for the turning of this device. I also took a
video of myself turning quickly, for the same purpose. I
learned that the turning target speed and my turning speed were
effectively the same (20 frames or 0.66 seconds), which agrees
exactly with the Tobin and Fackler study cited by Ayoob above.
I assumed this would be so because it was an intentional design
feature of the equipment I manufacture, but I captured the video of
both just to prove the similarity in turning speed and to have the
proof available as needed.
Then, I took this unit and my video camera (Canon VIXIA HF R300) to
the Deer Creek Shooting Center to test some other subjects and their
ability to engage this turning target. I set up for the
shooters to shoot from seven yards from the target.
Setup for turning target testing
I captured data from a total of ten shooters of various experience
levels, ages, gender, and backgrounds. All test subjects had
some experience and training. Some had a lot.
I had each shooter try the challenge beginning in three different
starting positions. These three starting positions were:
1. "Sighted in" - pistol in a two-handed grip, pistol held at
eye level, sights on the target;
Demonstration of "sighted in" position by the author
2. "Low ready" - pistol in a two-handed grip, pistol held at
abdomen level, pointed down range (the classic "search position");
Demonstration of "low ready" by the author
3. "At side" - pistol in a one-handed grip, held at side
pointing 45 degrees down.
Demonstration of pistol at side by the author
In each position, the shooter had the pistol in this
condition: Magazine inserted, chamber loaded, safety off, not
decocked, finger off the trigger and on the pistol frame above the
trigger guard. For this make and model of pistol, this
condition of the pistol is the one in which the pistol is most
quickly ready to fire - it only needs the trigger pressed with a
light, single-action stroke to fire.
According to my reconstruction of the incident, my interviews, and
in my judgment, the low ready position used is the most similar to
Smith's position at the moment of encounter.
Smith was moving through the house. It is very difficult to
walk, maintain balance, and hold a gun up at eye level with two
hands. That would make the sighted in position less than
likely. However, given the tenseness of the situation, I doubt
that Smith would have had the pistol down by his side. Those
reasons, in part, explain why the low ready position, or some
variation of that, would best simulate Smith's condition at the time
of the incident.
Other "ready" positions. There are other "ready" positions
that may be used in this sort of situation, some made popular
through movies and television, and some that are taught by competent
trainers. One is "high ready," which has the pistol held in a
two handed hold and about four to six inches below eye level, barrel
horizontal, muzzle pointed straight down range. Another is a
sort of movie port arms, another two-handed hold on the pistol, but
with the pistol held at the shooter's forehead level, muzzle up, and
off-center to the side to allow the shooter to see around the hands
and pistol. Another is the small-town-cop low ready, also a
two-handed hold, arms straight with elbows locked, with the pistol
held below waist level, and with the muzzle pointed down just in
front of the shooter's feet. Perhaps the last is a
professional chest-ready, with the pistol at chest level, held tight
against the chest, held firmly in the dominant hand and the
non-trigger fingers of the non-dominant hand cradled into the web of
the thumb and index finger of the support hand, with the muzzle of
the pistol pointed down and forward of the feet.
There was simply not time available to test all of these various
ready positions in the test needed for this situation. And,
all of these other ready positions are essentially the same in
time-to-shot as the low ready position tested. If a shooter
must move a pistol from some ready position and into a sighted-in
position to take an accurate shot, the time-in-transit for the
pistol from the ready position to the shooting position will be one
of the shorter parts of the whole process, and will be about the
same from all mentioned ready positions.
The pistol used by all of my volunteer test subjects was an exact
twin to the one used in and recovered from the Smith incident.
The only difference is the serial number.
Pistol from the incident on left; pistol used in tests on right.
About this Star 9mm pistol, and just for background, there are a
surprising number of conditions in which this pistol can be
kept. This Star has an exposed hammer and a combined safety
and decocking lever. The decocking lever brings the hammer to
rest in the forward position. The safety moves the rear of the
firing pin forward of the rear face of the firing pin stop, making
it impossible for the hammer to contact the firing pin. Other
than those, this pistol's features are standard for a self-loading
pistol. Here are the various conditions in which this pistol
can be kept:
1. Empty with no magazine in the pistol and no round in the
2. A loaded magazine in the magazine well, no round in the
chamber, and the safety in the no-fire position. (The
consequence of the safety being in the no-fire position is that if
the slide is racked to transfer a round of ammunition from the
magazine to the chamber, the pistol still will not fire.)
3. A loaded magazine in the magazine well, no round in the
chamber, and the safety in the fire position. (The consequence
of the safety being in the fire position is that if the slide is
racked to transfer a round of ammunition from the magazine to the
chamber, the pistol will then fire if the trigger is pressed.)
4. A loaded magazine in the magazine well, a round in the
chamber, the safety in the no-fire position and the hammer
decocked. In this condition, a long, double-action pull will
cycle the trigger and hammer, but will not fire the pistol because
with the safety in the no-fire position the firing pin is held
forward of the firing pin stop, inaccessible by the hammer.
5. A loaded magazine in the magazine well, a round in the
chamber, the safety in the no-fire position, and the hammer
cocked. In this condition, a light, single-action trigger pull
will drop the hammer from the cocked position, but it won't fire the
pistol because with the safety in the no-fire position the firing
pin is held forward of the firing pin stop, inaccessible by the
6. A loaded magazine in the magazine well, a round in the
chamber, the safety in the fire position and the hammer
decocked. In this condition, a long, double-action pull will
cycle the trigger and hammer, and fire the pistol.
7. A loaded magazine in the magazine well, a round in the
chamber, the safety in the fire position and the hammer
cocked. In this condition, a short, single-action pull will
fire the pistol.
It is believed that condition #7 above is the condition the Smith
pistol was in at the time of the confrontation in the Smith
home. This is the condition in which the pistol may be most
quickly fired. Any of the other conditions would take longer
to fire than #7. Because of that, it is the condition for the
pistol used by volunteers in the tests. Volunteers were
instructed to begin with their trigger finger on the frame, above
the trigger and trigger guard, but not on the trigger, a standard
firearm safety practice.
The test subjects were told that as soon as they detected movement
from the mannequin target, they should fire one shot at the center
of mass (center of chest) of the target. When the subjects
started at the low ready, all subjects raised the pistol to eye
level before firing. When they started with hand at side, most
raised the pistol into a two-hand grip at eye level before firing,
although a few fired with only one hand on the pistol.
While I believe some version of the classic low ready/search
position is the one Smith found himself in at the moment of final
encounter with the intruder, I tested all three of the positions
listed above. To score the test shooters, I examined the
mannequin after each shot to determine the angle of bullet passage
through the mannequin. I scored each shot according to whether
the mannequin was fully facing the test shooter, 1/4 of a turn away,
1/2 of a turn away, 3/4 turned away, or fully turned away from the
test shooter when the bullet passed through the mannequin.
After each shot, I put a square of white tape over any entrance and
exit holes so the bullet path would be obvious for subsequent
shots. The result of the testing was:
1. Sighted in. None of the volunteers were able to
trigger a shot while the front of the target was facing them.
Four of ten triggered a shot when the target was 1/4 turned
away. Five of ten triggered a shot when the target was 1/2
turned away. One of ten triggered a shot when the target was
3/4 turned away.
2. Low ready (the assumed position of Smith during the
incident). Ten out of ten volunteers tested made their shot
after the turning target had fully turned away.
3. Pistol at side. Ten out of ten volunteers tested made
their shot after the turning target had fully turned away.
It is no surprise that those volunteers who were able to trigger a
shot when the target was only 1/4 turned, and only from the
sighted-in position, were the more experienced shooters. Those
included one Army veteran recently returned from multiple tours in
Iraq and Afghanistan, and a competitive pistol shooter with years of
experience in the sport of practical pistol (a sport that develops
and requires speed and accuracy with handguns).
For a target turning at the same speed I can turn (a 68 year old
male), and with the test subjects starting in the most likely start
position, the low ready "search position," ALL of those tested shot
the mannequin in the back. That is, the mannequin had spun a
full 180 degrees by the time EVERY person tested fired their single
shot. That's 10 out of 10 tested subjects got hits on the back
of the turning dummy target when shooting as quickly as possible,
triggered by sudden movement. Three of the subjects shoot
competitively in the sport of practical pistol, all subjects had
some firearms training, and one was a recent Iraq veteran. All
volunteers were recruited at a shooting range, so all had some
interest in firearms just to be present and available for
recruitment and this test. I'd say all members this group of
test subjects probably had skills and abilities at least equal to
Smith's, and probably superior to his.
See the attached videos of my test subjects shooting. In
compiling and editing these videos, some things were done to make
them more understandable by the viewer. Included first are a
few seconds of each test subject engaging the turning mannequin at
real time speed - unedited except for clipping the segment from
longer periods of non-relevant activity. However, this happens
so quickly for each shooter that it's difficult to see exactly when
the shot breaks in relation to the turning mannequin. So, for
each test subject, the shot was also repeated with a short, slow
motion clip including when the actual shot was fired. And, in
the slow motion repeat the clip was paused briefly at the exact
moment that the gunshot broke, so the viewer can see the extent to
which the mannequin was turned at the instant of the shot.
Thanks to Ty Marbut for the video editing and production.
Pointed down video
Pointed in video
In final answer to this question, yes, there is a perfectly
reasonable explanation, even if not obvious, for why the entrance
wound in Jones can be in the back and Smith can still be accepted to
have used lethal force in a justifiable manner. I have
documented, explained, and demonstrated that reason in the testing
performed, recorded, and described here.
About the author: Gary Marbut is accepted in state and federal
courts as an expert
concerning self-defense, use of force, firearm safety, and related
topics. Gary is the author of Gun Laws of Montana,
now in its Fifth Printing. He is a veteran firearms instructor,
manufactures shooting range
equipment for law enforcement agencies nationwide, is
president of the Montana Shooting
Sports Association, and competes in two different shooting