Maybe 21 Feet Isn't Too Close?

Another knife attack study.

Publication

Michael A. Kantor, Susannah Reiner & Robert W. Pettitt (2024) Evaluation of Tactical Movement and Firearm Draw Performance During Charging Knife Attacks, Police Practice and Research, 25:1, 101-109, DOI: 10.1080/15614263.2023.2222872

What Was the Issue?

This is another study that looked at the ability of officers to draw and fire before a knife wielding suspect could reach them (this post reviewed a knife attack study that we published). This study explored the effects of different distances and movement strategies on survivability.

How Did They Look at It?

The researchers recruited 20 law enforcement officers from the same department. This department invested about $1000 per year per officer in firearms training. All the officers were equipped with the same level 1 retention holster and a training pistol loaded with two marking rounds. Three different movement tactics were used: stationary, 90 degree lateral movement (toward the officer’s dominant hand), and backpedaling. Four different distances were evaluated: 10 feet, 15 feet, 21 feet, and 30 feet. Participants started with the attacker at the closest distance and were randomly assigned an order to perform the defensive tactics in. The attacker would rush the officer and the officer would try to draw and fire before the suspect reached him with a rubber knife. When these runs were complete, the attacker moved back to the next distance, and a new random assignment of tactic order was assigned. This process was repeated until the participant had completed 12 total runs (3 movement tactics at each of 4 distances).

What Did They Find?

The primary outcome that they were concerned about was survivability. The exchanges were coded as survivable if the officer was able to fire 2 shots before the suspect was able to make contact with the knife. Survivability rates by condition are presented in the chart below. Survivability increased as the distance between the suspect and officer increased. Also, lateral and backpedaling movements produced better results than standing stationary.

There is other interesting information in the paper about how fast the officers fired between shots and the change in draw and fire times as the suspect got further away.

So What?

This study produced results that were a little different than the research that we conducted. Specifically, they found that 21 feet of distance between the officer and suspect was enough for the officers to fire twice before the suspect made contact in 95% of the runs. We estimated that 32 feet was needed for 95% of the officers in our study to be able to fire a single shot before the suspect reached them.

We think that this difference is essentially due to differences in draw and fire speeds on the part of the officers in the two studies. In this study, it took officers 1.09 seconds on average to fire two shots when the suspect was 21 feet away. In their data, the second shot was fired about .24 seconds after the first at 21 feet. This means that their officers fired their first shots in about .85 seconds (1.09 - .24). That is fast! Our officers fired their first (and only) shot in 1.43 seconds on average. They were more than a half second slower!

The obvious question is why? The short answer is that we can’t know for sure, but there are several possibilities. First, the officers in this study may have simply been more skilled. Second, the level one retention holsters in this study may have allowed officers to draw faster than the variety of holsters that were used in our study. Third, in this study, the attacker used a rubber knife. In our study, the attacker used a shock knife. The shock knife might have produced more stress, and this stress may have interfered with the ability of the officers to draw (several officers in our study failed to draw at all). While I think that all of these issues could have played a role, I think the best explanation is that the officers in this study knew that the attacker was going to charge them, and this allowed them to react faster. The fast .85 second reaction times in this study are in line with the performance of good shooters on a range reacting to a timer beep. In our study, the attack was a surprise. We told the participants that they would go through several scenarios that may or may not involve the use of a training weapon. Additionally, in our study, the participants had to talk with the suspect for a few minutes before the suspect charged. So, in our study, the officers had to realize that the attack was occurring and then respond; whereas in this study they knew the attack was coming and could start drawing as soon as the suspect moved. Recognizing an attack and then responding simply takes longer than responding to a suspect’s first movement.

Whatever the reason for the differences in this study and our study, both studies agree that moving (either laterally or away from a suspect) reduces the officer’s chances of being stabbed. Add the data in these studies to the data on police shootings, which clearly show that actual shootings involve movement, and it becomes difficult to argue that we should be teaching shooting from stationary positions.

Yet, how often are we training officers to move as they shoot? Almost all the range training that I have observed involved officers standing in fixed positions and shooting. Obviously, there are safety concerns here, but it is possible to have people move safely during range training. It just takes forethought, effort, and accepting that you cannot move as many people through courses of fire as quickly as when they are stationary. For some initial thoughts in this direction see the posts here and here.