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May 26, 2011

New reaction-time study addresses what’s ‘reasonable’ in armed-suspect encounters

You are confronting an armed suspect, no cover available. He faces you, with his gun at his side, pointed at the ground. Your gun is aimed at him and you’re ready to shoot. He ignores your commands to drop his weapon.

Are you justified in pulling the trigger before he makes any move to point his gun at you?

According to conclusions reached by researchers in a unique new reaction-time study, your preemptively shooting under such circumstances may well be considered reasonable by the standards of Graham v. Connor.

If the offender suddenly points his gun in your direction, you are highly unlikely to get a shot off to defend yourself before he shoots, the researchers documented. Even under ideal circumstances, you probably can fire no faster than simultaneously with the attacker.

These findings “serve to illustrate the extreme danger that armed suspects present to police officers,” the researchers report. “Even when a police officer has his or her gun aimed at [an armed] suspect and the suspect is not aiming at the officer, the officer is still in extreme danger....

“The reasonableness standard [set forth by Graham] is based on what a well-trained, prudent officer would do in a given situation.... Our results show that even well-trained officers...with their guns aimed at a suspect cannot reasonably be expected” to react faster than a suspect can raise his or her gun and fire.

“This is an important study that advances the understanding of the dynamics of deadly force encounters, which often are quite different from the perceptions held by the general public and the media,” says Dr. Bill Lewinski, executive director of the Force Science Institute. “While the Institute was not involved in this project, the findings are fully compatible with our earlier discoveries regarding officers’ reaction times in life-threatening situations.”

The new study was headed by Dr. J. Pete Blair, an associate CJ professor at Texas State University and a former interviewer/trainer for John E. Reid & Associates. His investigative team included representatives of the Advanced Law Enforcement Rapid Response Training (ALERRT) Center at the university and was supported financially by the CJ Division of the Texas governor’s office.

Test Set Up
“Suspects” in the research were 30 male and female CJ students, averaging about 22 years old and mostly Caucasians. The test subjects were 24 male volunteers recruited from an active-shooter training class at a regional SWAT conference. They averaged nearly 10 years’ policing experience, with nearly five years on SWAT, and were considered “elite...particularly [in] the use of deadly force.” They averaged about 34 years old and slightly more than half were Caucasian.

Armed with a Glock training pistol that fired marking cartridges, each officer progressed through a series of 10 rooms in an abandoned school, presumably in response to a “generic ‘person with a gun’ call.” In each room, the officer confronted a suspect armed with a similar pistol at a distance of 10 feet. In some cases, the suspect’s gun was at his/her side, pointed at the floor. In others, the gun was pointed at the suspect’s own head in a suicidal pose.

According to prior instruction, one-fifth of the suspects followed the officer’s order to surrender peaceably. The rest, designated as attackers, were told to try to shoot the officer any time they chose “after an initial command to put down the gun was given.” In all cases, officers had their gun up and on target at the outset of the encounter and were instructed to “attempt to shoot first” as soon as they perceived a move to shoot them.

Later, the research team conducted a meticulous frame-by-frame analysis of video recordings of 159 of the shooting exchanges.

Reaction Time Results
Analysis showed that the suspects on average were able to fire in just 0.38 second after initial movement of their gun. Officers fired back in an average of 0.39 second after the suspect’s movement began.

Specifically, suspects moved the gun up from their side and fired in an average of 0.36 second and from their head, on average, in 0.40 second. The average officer responded fractionally faster to movement from the side (0.38) than to movement from the head (0.40).

Statistically, the researchers point out, the hair-splitting differences between these various measurements are inconsequential. The initial gun position “did not appear to significantly affect the firing times of suspects,” the team reports. Nor did it “appear to affect the speed with which the officers fired.” Overall, “officers and suspects appear to have fired at about the same time.”

The miniscule edge did go to the suspects, technically. Examined case by case, they shot faster than officers or precisely simultaneously in more than 60% of the encounters. “Even in situations where the officer was faster, there was less than a 0.2-second difference, suggesting that the suspect would still get a shot off in most of these encounters,” the researchers state.

“The process of perceiving the suspect’s movement, interpreting the action, deciding on a response, and executing the response for the officer generally took longer than it took the suspect to execute the action of shooting, even though the officer already had his gun aimed at the suspect.”

And this was in near-ideal conditions from the officers’ perspective. The volunteers were “highly experienced” and “knew they would be encountering suspects with guns.” The confrontations took place in “well-lit rooms,” with only a single offender, “with both parties remaining stationary,” with no distractions, with no attempts by the suspects to deceive the officers by feigning compliance before shooting, with officers not nearly as stressed as they would be “during an actual life-or-death situation,” and with none reporting “confusing sensory and perceptual distortions.”

Moreover, “the suspects extended their arms to bring the gun in line with their eyes before shooting in almost every exchange,” rather than “simply rotating the gun and firing.” Thus their assault was slower than a spontaneous street encounter might be. The researchers concede that “many of the elements that occur in real-life shootings” would doubtless add significant time to the average officer’s reaction time.

The good news in this study concerns accuracy. Suspect role-players, largely untrained in gun-handling, scored hits only about half the time. With their already on target, officers were able to successfully shoot suspects nearly 90% of the time. This is contrasts with actual OISs, where the reported police accuracy rate is “generally less than 50 percent,” the study team notes.

“Police officers have a legal right to use force, including lethal force, when it is reasonable to do so,” the researchers state. “An officer may shoot when there is an imminent risk of harm to self or others, or to stop someone who poses a danger to others if allowed to escape....

“There is a perception amongst some community members that officers are too quick to shoot those who only appear to pose a threat.... There are people who seem to believe that the ‘reasonable’ officer should wait until a suspect with a gun begins to use the gun against the officer before the officer utilizes lethal force. [But] would waiting be reasonable in situations where the suspect has his weapon in hand but not aimed?”

That’s the critical question Blair’s study addresses. “As our findings show, most officers can’t fire faster than a suspect with a weapon in hand, even if it is not aimed at the officer,” his team writes. Consequently, “we think that an officer who decided to shoot [in the kinds of situations tested] meets the legal definition of reasonableness,” given the “close range of the encounter, the lack of available cover, the failure of the suspect to comply with multiple warnings, and the data” collected.

The researchers stress, however, that they “do not believe that the findings support” automatically shooting “everyone with a gun” or “everyone with a gun who does not comply.” Armed encounters vary in their details, and “the individual officer must consider the totality of circumstances” in choosing a fitting response, including whether issuing commands is feasible or desirable before firing.

The researchers believe that certain training implications are clear from their findings. First, they support having officers participate in scenarios similar to those they used to convey “a better understanding of the dynamics involved” in armed confrontations and to “help correct inaccurate beliefs about shooting ability.” Also they believe training should “teach officers how to mitigate the dangers posed by armed suspects” through such means as distance and cover.

They hope that their findings “will help officers, and those who judge the actions of officers, to make more informed decisions about the reasonableness of officers’ actions” in deadly encounters.

A full report on the study has been accepted for publication later this year in the peer-reviewed journal Police Quarterly. Publication can be tracked here.

Meanwhile, Blair has 2 research projects on the board that Force Science News will be following up on in the future. He is underway with a study of room-entry tactics, designed to identify which technique is fastest for revealing subjects hidden in corners, best suited for accurate fire from officers, and least conducive to hits from offenders.

He plans also to comprehensively catalog and analyze active-shooter incidents. Results from the building-entry study, at least, are expected by this fall.

About the author

The FSRC was launched in 2004 by Executive Director Bill Lewinski, PhD. - a specialist in police psychology -- to conduct unique lethal-force experiments. The non-profit FSRC, based at Minnesota State University-Mankato, uses sophisticated time-and-motion measurements to document-for the first time-critical hidden truths about the physical and mental dynamics of life-threatening events, particularly officer-involved shootings. Its startling findings profoundly impact on officer training and safety and on the public's naive perceptions.

For more information, visit or e-mail If you would benefit from receiving updates on the FSRC's findings as well as a variety of other use-of-force related articles, please visit and click on the "Please sign up for our newsletter" link at the front of the site. Subscriptions are free.

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Posted by ec9666 on Monday, May 30, 2011 06:21 PM Pacific  Report Abuse
Outstanding article, and a well conceived and executed study. It's reassuring to see more evidence emerging to assist the police, rather than to bring us down. Thanks to P1 and FSRC for passing along the information.
Posted by USO131 on Monday, May 30, 2011 04:01 AM Pacific  Report Abuse
ghostvet - you are partly correct.
Seeing a subjects movement and acting is too late YOU ALSO HAVE TO PAY CLOSE ATTENTION to their body language. Don't just tunnel vision on the weapon; WATCH THEM. You will see the signs just before they move and you will then be way ahead of them.
Posted by jscrivner on Saturday, May 28, 2011 10:11 PM Pacific  Report Abuse
Does anyone have any contact info for the researcher in this study? I would love to get some video clips from the study to incorporate into UOF training.
Posted by ghostvet on Thursday, May 26, 2011 02:01 PM Pacific  Report Abuse
On the face of it, this seems contrary to common sense- bad guy has to move a whole arm and bring it up and then squeeze a trigger, while the cop has only to squeeze a trigger.

But then on further, the explanation makes perfect sense- the bad guy has already decided what to do and has only to act. The cop has to see the movement, recognize it as a threat and then respond!

Gotta love FSRC!- and Dr Blair of course!
Posted by Salad on Thursday, May 26, 2011 10:27 AM Pacific  Report Abuse
Do...not...wait for someone to kill you! Common mistake #1...
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