The purpose of this study was to scientifically assess the long-standing 21-foot rule. There are several anecdotal publications looking at the 21-foot rule as a standard in policing. This study uses experimental design to examine whether this standard should continue in modern-day policing. The 21-foot rule was tested in three independent experimental design studies. The first study measured the average speed at which a person could run 21 feet. The second and third studies tested the speed at which an officer could draw and fire their weapon with no stress and under stress respectively. The final study examined methods for increasing survivability for the officer (movement). The findings show the 21-foot rule to be an inadequate standard for officers to safely draw and fire their weapons when being charged by a suspect who’s intent it to cause harm. Additionally, different strategies of moving can increase the officer’s ability to survive.

One key feature for scenario-based training is introducing stressful, realistic scenarios for trainees. Some law enforcement agencies have begun using virtual reality systems to provide scenario training for their officers. Therefore, the current study was conducted to assess if a virtual reality training scenario can elicit a similar stress response as a realistic scenario-based training scenario. The independent groups quasi-experiment collected salivary markers of acute stress (α-amylase and secretory immunoglobulin A) prior to, and immediately following, either an in-person scenario-based training exercise (n=31) or a virtual reality scenario (n=27) based on the in-person exercise. Difference-in-difference and two-way ANOVA tests were performed. Overall, participants exposed to the virtual reality scenario experienced a similar stress response to the realistic in-person scenario-based training exercise. Implications for law enforcement agencies are discussed to hopefully move police training forward.

Objective: This survey examined current law enforcement beliefs and practices about interviewing and interrogation to gauge whether they have evolved given the research and training developed over the past 20 years. Hypotheses: We hypothesized that police beliefs and practices would have evolved along with research findings over the past 20 years. Method: We surveyed 526 law enforcement officers about the practices and beliefs regarding interviewing and interrogation. We asked questions about officers' beliefs about rates of true and false confessions, time spent in the interrogation room, beliefs about their ability to detect deception, training experience, practices of recording interrogations, and their self-reported use of interrogation techniques. Results: Overall, when we compared our survey with Kassin et al.'s (2007) seminal survey, we found both similar results and evolving positive trends. The average interview was reportedly 1.6 hr, virtually no different from that in Kassin and colleagues' study. In addition, our sample reported that 26.2% of innocent suspects at least partially falsely confessed. Further, whereas Kassin and colleagues found that fewer than one in 10 interrogations were video recorded, we found that now more than half of interrogations are recorded in this way. Conclusions: In a geographically diverse sample of U.S. law enforcement officers, we found significant positive trends toward knowledge and practices informed by research generated over the past decades on interviewing and interrogation. Although causality could not be determined, these findings indicate an evolution of the U.S. law enforcement mindset in a more science-based direction. Public Significance Statement This survey found support for an evolving mindset of U.S. law enforcement officers regarding interviewing and interrogation beliefs and practices. We found that officers reported false confessions as more prevalent, recording of interrogations happened most of the time, and beliefs about deception detection showed a downward trend, compared with 20 years ago. All of these shifts are congruent with research on the topic and demonstrate a potential increase in awareness of the science.

Objective: High cardiorespiratory fitness (CRF) is associated with reduced markers of oxidative stress and cardiovascular disease (CVD) risk factors; however, this relationship has not been elucidated in firefighters. The purpose of this study was to examine differences in markers of CVD risk between firefighters who have either high or low levels of CRF. Methods: Forty-six firefighters participated in a maximal graded exercise test and a dual-energy x-ray absorptiometry scan and provided a fasted blood sample. V˙O_2max values were categorized based on American College of Sports Medicine guidelines to establish high- and low-fitness groups. Results: High fitness firefighters demonstrated significantly higher high-density lipoprotein cholesterol and lower markers of CVD risk: cholesterol, triglycerides, low-density lipoprotein cholesterol, insulin, homeostatic model assessment for insulin resistance, C-reactive protein, and advanced oxidation protein products concentrations. Conclusion: Firefighters are encouraged to maintain high CRF to reduce risk of CVD.

Police officers are frequently engaged in a variety of high-stress scenarios, such as high-speed chases and other suspect conflicts, that cause significant increases in a variety of physiological and psychological stress markers. The purpose of this study was to investigate salivary and blood markers of stress in response to an active shooter training drill (ASD). Thirty-one participants (n = 31; males = 15, females = 16; Age: 21 ± 3.5 years) participated in an ASD involving professional actors playing the role of one active gunman, as well as four victims. The ASD lasted approximately 50 s. Blood samples were collected 15 min prior as well as after the ASD and analyzed for epinephrine (EPI) and norepinephrine (NE) levels. Saliva samples were collected 30 and 5 min prior to the ASD and 5 and 30 min after the ASD, were analyzed for cortisol, α-amylase, and secretory immunoglobulin-A (SigA). The ASD resulted in significant (p < 0.05) increases in EPI, α-amylase, and SigA levels. The increase in NE from pre to post ASD approached significance (p = 0.06). These results demonstrate that a short duration (~50 s) ASD results in significant increases in both blood and salivary markers of stress. These data may provide meaningful implications for those engaged in high-stress tactical occupations, especially law enforcement and military personnel, as chronic exposure to such occupational stressors can contribute to cardiometabolic disease.

Tactical occupations regularly encounter life-threatening situations while on duty. Although these occupations are often trained to utilize slow breathing (SB) during intense stress, there is no evidence supporting the effects on markers of stress in response to a virtual reality active shooter training drill (VR-ASD). The purpose of the study was to determine the impact of acute SB on biomarkers of stress in response to a VR-ASD. Seventy-nine (n = 79) subjects performed either slow breathing method 1 (SB1), slow breathing method 2 (SB2), or normal breathing (control) for five minutes, both pre- and post-VR-ASD. Saliva samples were analyzed for stress markers, including α-amylase (sAA) and secretory immunoglobulin-A (SIgA). Both methods of SB resulted in significantly lower sAA concentrations at 5 (p < 0.001) and 30 min post-VR-ASD (SB1: p = 0.008; SB2: p < 0.001) compared to the control. In the control condition, the sAA concentrations were significantly elevated 5 min post-VR-ASD (p < 0.001) but did not change across time in SB1 or SB2 (p > 0.05). Thus, both SB1 and SB2 reduced the sAA response and resulted in lower concentrations post-VR-ASD. This study was pre-registered as a clinical trial (“Impact of Breathing Interventions on Stress Markers”; NCT05825846).