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