Physical Lag Times: The Use Of Deadly Force

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OTHER "TIME" FACTORS

In the course and scope of employment as a policeOTH officer, supervisor and
manager, the author has had the opportunity to review several hundred officer
involved shooting situations for training, officer safety, administrative use of
force review boards, courtroom presentations and internal discipline.
Following these examinations involving hundreds of investigative hours,
personal experience, evaluation of suspects actions and interviews of
"shooting" police officers, it has been the author's observation that:

1. A suspect armed with a pistol, secreted in his waistband, can draw and
fire at least two shots within 1.0 to 1.5 seconds.

2. Approximately 90% of all officer involved shooting incidents take place
within a three-second-time period.

POST INCIDENT ANALYSIS

As mentioned initially, during post-incident analysis, oftentimes conflicts arise
between an officer's statement and the actual evidence. Please consider the
following additional scenarios and explanations.

1. An officer stated during the officer involved shooting interview he
discharged his firearm in defense of himself when the suspect was facing him.
The forensic evidence indicated however, the bullet track was posterior to
anterior. Under the specific circumstances, perception time, brain lag and
reaction time of the officer, combined with continued movement of the target
(suspect), may have accounted for the inconsistency between the officer's
initial statement and the actual evidence.

2. A suspect believed to be armed with a handgun is chased by a police
officer. The suspect stops, turns to his right and partially faces the officer. The
suspect removes what appears to be a handgun from his waist, extends his
right arm, while turning to his right. He then makes a movement consistent with
assuming a shooting position. The police officer, in pursuit, perceives the threat
(0.1 second), stops, assesses that he is in imminent danger of being shot,
decides on the appropriate use of force and makes the decision to shoot (0.6
to 0.8 or more seconds). At this point, the suspect is continuing to move, turn,
bend, squat, run, climb, throw, stop etc.. In the beat of a heart, the officer
makes the decision to shoot, based upon the belief of imminent threat to life.
He acquires the target, aligns his front and rear sight and squeezes the trigger
twice in rapid succession (1.0 second or more). The suspect falls to the
ground shot in the back. Under the circumstances, the officer's perception of
the threat, decision to shoot plus actual shooting time, required at least 1.0
second or more to implement. During this period of time the officer observed
certain facts and decided on a course of action while the suspect's movement
continued. In closer examination, at the time the officer actually commenced
shooting one would probably find that the suspect was turning back, toward
his left when the bullet(s) impacted . During the post incident, officer interview
however, the officer may have recalled he discharged his weapon while the
suspect was facing him, when in reality, the suspect actually was in the process
of turning away from him.

This discrepancy does not mean the officer was being untruthful at the time of
the interview. Quite the contrary, the physical time lags affecting the officer, his
recall of the suspect's position at the moment he decided to shoot combined
with the continuous movement of the suspect after he started shooting, may
have accounted for the discrepancy between the officer's belief as to the
position of the suspect when he shot and the actual physical evidence. In other
words, the officer's reaction lagged behind the actions of the suspect.

It is also recognized that many factors can affect the above examples; tactics,
positioning, movement of the officer, accuracy and availability of cover, etc..
The point is, the physical time lags (perception time, brain lag and reaction
time) combined with the movement of both officer and target must be equally
considered prior to formulating opinions of what occurred.

As indicated previously, "crisis decisions," i.e., the use of deadly force, require
time (perception, brain lag and reaction time) in order to implement. Just as it
takes time for the police officer to perceive, decide and react to an impending
threat, it also takes time for the officer to perceive, decide and actually stop
his reactive measures. It has been the author's experience to note that criticism
has occasionally arisen regarding an "alleged" excessive number of rounds
being fired by a single "shooting officer".

An officer who is shooting to stop the actions of the suspect is required to
continuously assess the threat throughout the event, and when, in his opinion
the threat is stopped, must "de-escalate" his force. Under these circumstances,
the sequence of de-escalation requires time to implement. It is not unusual to
find that an officer may have attempted to cease fire after 2 to 4 shots
(depending upon the weapon) but, in reality discharged 10 shots or more. In
the final analysis, this alleged "excessive" number of rounds discharged may
not have been excessive at all, and may be attributed to the physical time lags
involved in the officer's deciding to de-escalate response. In short, the officer
may have been unable to immediately discontinue shooting after the initial 2 to
4 shots, due to the perception time, brain lag and reaction time required to
stop the action.

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PHYSICAL TIME LAGS AND DISTANCE

A suspect's proximity from a deadly weapon (e.g., arms reach) and a police
officer's distance from a suspect (lunging distance) coupled with the physical
time lags required for defensive reaction, can impact the decision to utilize
deadly force. Under specific conditions, a police officer may have no other
tactical options (e.g., cover, concealment, position etc.) and the threat of
serious bodily injury is "reasonably" present. The officer may be forced into a
deadly force situation in order to stop the suspect (e.g., movement towards
arming himself with a weapon). Officers are not expected to allow suspects to
arm themselves and then set about physically engaging and disarming them.
The law and use of force policies do not require officers to use the same or
lesser amounts of force to overcome a suspect's resistance. Police officers are
required to utilize that amount of force which is "reasonable" to overcome
resistance. "Grappling" with an armed suspect not only increases the risk to
the police officer, but tends to exacerbate and escalate the situation.

SUMMARY OF TECHNICAL AND TACTICAL POINTS:

1. The components of physical time lags are:

* Perception time 0.1 second

* Brain lag 0.1 second or more

* Reaction time 0.4 to 0.8 seconds

2. The sum total of physical time lags (perception time, brain lag and reaction
time) is generally between 0.75 and 1.0 second.

3. An armed subject with a firearm secreted in his waistband can draw and
discharge a minimum of 2 shots within 1.0 to 1.5 seconds.

4. Physical time lags, combined with continuous movement of a suspect, can
account for discrepancies between an officer's account of events and the
actual post-incident evidence.

5. A police officer's perception time, brain lag and reaction time all begin after
the suspect's actions are already underway.

6. A police officer's decision to de-escalate the use of deadly force is subject
to the same physical time lags as the decision to use deadly force.

7. Proximity of a suspect from a potential weapon (distance of a police officer
from the suspect), coupled with physical time lags, can effect the decision to
utilize deadly force.

8. The existence of physical time lags, perception time, brain lag and reaction
time does not justify the use of poor or inappropriate tactics.

9. Under life-threatening conditions, waiting to see a suspect's gun before a
police officer utilizes deadly force can result in injury and/or death to the
officer.

CONCLUSION

In conclusion, the post incident analysis of an officer involved shooting is
complex at best. It is hoped that those who sit in review of police officers’
actions consider the "fast moving circumstances" of the situation, the impact of
physical time lags and the officer's overall "state of mind" at the moment he
decided to shoot. The issues involving "physical time lags" are present, to
some degree, in most officer-involved shooting situations. Additionally, it is
this author's opinion that in some cases, these time lags have been given little
consideration when analyzing the totality of the involved police officer's
actions. The most stressful, emotionally impacting and permanent decision a
police officer can ever make is the decision to utilize deadly force. The best
those of us sitting in judgment can do is understand the totality of the
circumstances, the concept of physical time lags and their impact on the use of
deadly force.

About the Author:

Captain Michael Hillmann is the commanding officer of LAPD’s West
Los Angeles Area. His 33 years with the LAPD include assignments to
patrol, Anti-Terrorist Division, and the Special Weapons and Tactics
(SWAT) team. He has written articles for a wide variety of publications
and presented in-depth courses on tactics and emergency response to law
enforcement, the military, and private industry. He is widely regarded as
one of the premier experts in emergency response and tactics.

End notes:

1. Department of Transportation, Federal Aviation Administration, Civil
Aeromedical institute Physiological Operations, Physiological ing -
High Speed Flight, p. 24, January 1972.

2. Los Angeles Police Department, ing Division, Driver ing Unit,
Instructor Lesson Plan, "Vehicle Operation Factors", The Human Factor -
Reaction Time, C-1.

3. United States Supreme Court, Graham v. Connor (490 U.S. 386 - 1989).

4 Lt. Joe Callanan, (LASD retired) The Tactical Edge Magazine, Use of
Force After The Rodney King Incident, p.17, Fall 1992