Recommended Reading
ALERRT’s Research Team actively publishes results from ongoing research projects in a variety of scholarly outlets. Our team has published two book as well as a growing body of journal articles. You can click on the article titles to read a short summary. You can click “View the article here” under each summary to be directed to a PDF of the entire article. We will update this page as additional articles are published. You can email Dr. Hunter Martaindale ( with any questions related to these publications.


  • Active Shooter Events and Response by J. Pete Blair, Terry Nichols, David Burns, John R. Curnutt
  • Evaluating Police Tactics: An Empirical Assessment of Room Entry Techniques by J. Pete Blair and M. Hunter Martaindale

Journal Articles


Reasonableness and reaction time

Decisions made by police officers are typically judged according to a reasonableness
standard. This standard is based on what a well-trained, sensible officer would do in a particular situation. The current article used an experiment to assess the reasonableness of an officer’s response to an armed suspect using 30 participant “suspects” and 24 officers. Each officer in the experiment, with their gun drawn and aimed at a suspect, was presented with an armed suspect who was not initially aiming at the officer. The suspect either shot at the officer or surrendered. Reaction times were assessed, revealing that officers fired at the same time or later than the suspects 61 percent of the time. These results
suggest that, in this scenario, officers cannot reasonably be expected to shoot before the suspect raises his or her gun and fires. Therefore, officers should
avoid situations like the one depicted in the scenario, where they are without cover and distance when facing an armed suspect.

View the article here.


Active-shooter events in the workplace: Findings and policy implications

The current article provides an in-depth examination of 105 active shooter events (ASEs) in the workplace that occurred from 2000-2015, which include three main
categories: factories and warehouses (26), offices (29), and retail locations (50). Overall, 619 people were shot, and 282 people were killed in ASEs at businesses during this period. Attacks were more likely to occur during standard business hours, with a spike at 7pm. In all but two cases, the ASE involved a single shooter. Most (55%) of the events ended before police arrival. By contrast, 45 percent of the ASEs ended after police arrival. To promote a safe work
environment, business owners and management may consider (1) utilizing a systematic strategy to detect, assess, and manage individuals that may pose a threat to others (threat assessment), (2) training employees how to respond effectively to ASEs, and (3) making physical security changes to buildings (access control).

View the article here.

Throwing a chair could save officers’ lives during room entries

Conducting building searches and room entries can place law enforcement officers in danger. The purpose of this study was to examine whether throwing everyday objects at suspects could improve officer safety by distracting the suspect. The study involved an experiment using 113 participants playing the role of a suspect hiding in the “blind” corner of a room facing the door. The research team member playing the officer either made a traditional room entry or had another team member throw a chair into the room before making the traditional room entry. Throwing a chair distracted the participant suspects by slowing down their reaction time, although it did not affect their shooting accuracy.
In addition, about one third of participants fired at the chair before officers entered the room. If an officer must conduct a room entry, throwing a chair or other plainly visible object might save the officer’s life.

View the article here.


The evolution of active shooter response training protocols since Columbine: Lessons from the Advanced Law Enforcement Rapid Response Training Center

The Columbine High School shooting that occurred on April 20, 1999 changed how law enforcement prepare for active attacks. Training centers were created in response to the need for this specific type of training, including the Advanced Law Enforcement Rapid Response Training (ALERRT) Center, which was formed in 2002 and named the national standard in active shooter training by the Federal Bureau of Investigation (FBI) in 2013. Since then, ALERRT has trained over 130,000 first
responders from over 9,000 agencies. The current article describes how active shooter training has changed in the wake of the Columbine shooting.

View the article here.

Peek or push: An examination of two types of room clearing tactics for active shooter event response

Solo officer response has become a new trend in active shooter response. The current study evaluates two commonly taught solo officer techniques (the peek and the push) for clearing rooms to determine whether the technique affects the shooting accuracy of the suspect. During a peek entry, the officer keeps as much of his or her body in the hallway, allowing only the head, shoulders, arms, and weapon into the room. Conversely, the officer enters completely into the room when conducting a push entry. An experiment was conducted with 165 student participants playing the role of the suspect. Armed with a training pistol, participants were randomly assigned to a room entry with an officer using either the peek or push technique. Findings suggest limited differences in suspect shooting accuracy between the peek vs. push method of room entry, although officers in the peek condition were moderately more likely to be shot in the head with the training pistols. Findings also suggest that suspects in the push entry are more likely to shoot before the officer than suspects in the peek entry.

View the article here.


A scientific examination of the 21-foot rule

The 21-foot rule is taught in training across the country to police officers as either a) the minimum distance that a suspect can cross and attack an officer with a knife before the officer can draw and fire his or her weapon, or b) a safe distance to deal with potentially dangerous suspects armed with knives. This article reports the results of four studies designed to test the adequacy of the 21-foot rule in practice. Results do not support the idea that 21 feet is a safe distance for an officer to stop a charging suspect. Further, having officers move while drawing and firing their weapon, as opposed to remaining stationary, may increase officer safety in these situations.

View the article here.

Correlates of the number shot and killed in active shooter events

Although there has been much research on various aspects of active shooter events, little attention has been given to the factors related to the number of people shot or killed in such events. The current study explored these factors. Results generally revealed that as the number of weapons brought to the scene
increased, the number of people shot also increased, and this effect was larger for the number of rifles compared to other weapons. Weapon type and number had
a smaller impact on the number of people killed than on the number of people shot. Schools were estimated to have one to two fewer people shot than other location types. Further, more recent attacks were estimated to have about one fewer person shot and one fewer person killed. Lastly, events in which potential victims stopped the attacker had the fewest estimated number of people shot.

View the article here.

Active shooter training drill increases blood and salivary markers of stress

Police often encounter high-stress situations, such as high-speed chases and other suspect conflicts. The current study examined changes in salivary and blood markers of stress in response to an active shooter training drill. Thirty-one participants took part in the training drill, which included professional actors playing the role of one gunman and four victims. Blood and saliva samples were collected from participants prior to and following the 50-second training drill. Results suggest that a short duration active shooter training drill can increase both blood and salivary marker of stress.

View the article here.


Women demonstrate lower markers of stress and oxidative stress during active shooter training drill

Police frequently engage in high-stress situations that increase a variety of physiological and psychological stress markers. The current study examined differences in male and female salivary and blood markers of stress in response to an active shooter training drill that involved professional actors playing the role of one gunman and four victims. Thirty-one participants took part in the training drill. Blood and saliva samples were collected prior to and following the 50-second training drill. Results revealed increases in stress levels for both male and female participants. However, four of the seven stress markers were lower in female participants compared to male participants.

View the article here.

Improving the accuracy of firearm identification in a dynamic use of force scenario

Use-of-force decisions must often be made in a matter of seconds (or less). The presence of a weapon may impact this decision-making process. Therefore, the speed and accuracy of weapon identification is especially important in use-of-force scenarios. The current study examined whether a brief vision-training program could increase the speed and accuracy in which participants identify an object as a gun in a use-of-force scenario. Results revealed that the participants who received the training were about 16 percent faster and made about 33 percent less errors when identifying the object compared to the participants who did not receive the training. These findings suggest that a simple vision-training program can significantly improve participants’ ability to correctly identify the presence of a firearm in a dynamic use-of-force scenario.

View the article here.


Police are sometimes required to conduct searches for hostile suspects in low light conditions. Police with routinely use a flashlight to help with their search. This study evaluated three of the most commonly taught flashlight tactics to assess if any could reduce the likelihood of a police officer being shot by a hostile suspect. Ultimately, the study found the Dagger technique reduced the likelihood that participants playing the role of a hostile suspect would successfully shoot the officer in a controlled setting.

View the article here.



Active shooter events occurring in schools generate widespread public concern and a demand to “do something.” One such policy that has gained traction following the 2018 shooting in Parkland, FL is arming teachers. This study used a nationally drawn sample of law enforcement. Ultimately, we found that law enforcement overwhelmingly supports armed teacher policies, but the support is contingent upon concerns related to training. 

View the article here.


This project utilized a nationally drawn sample of law enforcement officers to answer questions regarding their attitudes about armed teacher policies. Law enforcement officers provided insights on their attitudes regarding the capabilities of armed teachers, training considerations, as well as firearm and proficiency certification policies. This project utilized a nationally drawn sample of law enforcement officers to answer questions regarding their attitudes about armed teacher policies. Law enforcement officers provided insights on their attitudes regarding the capabilities of armed teachers, training considerations, as well as firearm and proficiency certification policies. 

View the article here


Virtual reality (VR) has emerged as a training tool for law enforcement. While VR is expected to provide a stressful environment for law enforcement to train, little is known about the acute stress response from VR exposure. This study examined the impact of participating in a VR-based active shooter scenario on markers of physiological stress using salivary based measures of stress (e.g., alpha-amylase and secretory immunoglobulin-A [SIgA]). Participating in the VR active shooter scenario resulted in an increase in salivary stress markers. 

View the article here


Active shooter events have driven police to change how they respond to events where an attacker is actively engaged in killing civilians. This paper examines these changes through the lenses of Normal Accident Theory (NAT) and Resilience Engineering (RE). Our results show a police officer is shot in one out of every six active shooter events in the United States. We apply RE to better understand how these shootings occur so that police can improve their ability to anticipate, monitor, and respond during these attacks. 

View the article here

Uvalde Texas - After Actions