Associations between police lethal force errors, measures of diurnal and reactive cortisol, and mental health.

Errors in lethal force by police are met with significant demand for explanations as to why they occur, stimulating a growing body of multidisciplinary research. Acutely stressful occupational conditions result in decrements to police performance, including lethal force decision-making. Further, although it is known that repeated and prolonged exposure to potentially traumatic work-related encounters is linked to higher rates of mental health symptoms, it is unclear if psychological symptoms are related to police performance, and lethal force errors specifically. The present study tested the relationships between biological stress and psychological symptoms on lethal force errors among a combined sample of non-clinical, active-duty frontline (n = 57) and tactical (n = 44) police officers. Specifically, biological measures included: diurnal (cortisol awakening response - CAR), and reactive cortisol (prior to and in response to realistic critical incident (CI) simulations). Psychological self-reported symptoms included: pre-CI stress, depression, anxiety, PTSD, and occupational stress. Tactical officers displayed higher CAR compared to frontline officers, consistent with prior research. When including outliers, CAR significantly predicted lethal force decision-making errors; however, the effect does not remain once removing the influence of outlier CAR observations. The current findings suggest that biological measures of reactive cortisol may be too nonspecific to predict lethal force errors during acutely stressful police operations and measures of diurnal cortisol are heavily influenced by outlier values. Non-clinical levels of psychological symptoms (as measured in this study) do not appear to interfere with lethal force decision-making. It remains to be tested if clinically diagnosed disorders would interfere with police performance. Implications for future applied health research are discussed.

Considering Objective and Subjective Measures for Police Use of Force Evaluation.

In spite of significant interest in the application of police use of force (UOF) from organisations, researchers, and the general public, there remains no industry standard for how police UOF is trained, and by extension, evaluated. While certain UOF behaviours can be objectively measured (e.g., correct shoot/no shoot decision making (DM), shot accuracy), the subjective evaluation of many UOF skills (e.g., situation awareness, SA) falls to the discretion of individual instructors. The aim of the current brief communication is to consider the operationalisation of essential UOF behaviours as objective and subjective measures, respectively. Using longitudinal data from a sample of Canadian police officers (n = 57) evaluated during UOF training scenarios, we discuss how objective and subjective measures reflect changes in officer performance over time. Objective lethal force DM was measured as a binary 'correct-incorrect' outcome and subjective SA was measured on a 5-point Likert scale ranging from 'unacceptable' to 'exceptional'. Subjective evaluation of SA demonstrated significant changes over time, while DM remained relatively high and stable. Given the practical and professional implications of UOF, we recommend that a combination of objective and subjective measures is systematically implemented at all stages of police UOF training and evaluation (i.e., basic, advanced, in-service).

Inferior Auditory Time Perception in Children With Motor Difficulties.

Accurate time perception is crucial for hearing (speech, music) and action (walking, catching). Motor brain regions are recruited during auditory time perception. Therefore, the hypothesis was tested that children (age 6-7) at risk for developmental coordination disorder (rDCD), a neurodevelopmental disorder involving motor difficulties, would show nonmotor auditory time perception deficits. Psychophysical tasks confirmed that children with rDCD have poorer duration and rhythm perception than typically developing children (N = 47, d = 0.95-1.01). Electroencephalography showed delayed mismatch negativity or P3a event-related potential latency in response to duration or rhythm deviants, reflecting inefficient brain processing (N = 54, d = 0.71-0.95). These findings are among the first to characterize perceptual timing deficits in DCD, suggesting important theoretical and clinical implications.

Diurnal Cortisol Variation According to High-Risk Occupational Specialty Within Police: Comparisons Between Frontline, Tactical Officers, and the General Population.

OBJECTIVE: The aim of this study was to compare diurnal salivary cortisol among high-risk occupational police specialties and the general population (n = 18,698). METHODS: Tactical and frontline officers provided salivary cortisol samples for 2 days (four times: wake, 30 minutes, 11 hours, and 17 hours post-awakening) and were compared with a general population sample of group field studies utilizing similar methodology. Samples were analyzed for free cortisol concentrations (nmol/L) using chemiluminescence immunoassay. RESULTS: Repeated-measures mixed-model analysis of variance (ANOVA) revealed significantly greater salivary diurnal cortisol among tactical than frontline officers. Furthermore, both tactical and frontline officers had higher cortisol levels on average at all time points than the general population sample. CONCLUSION: Results suggest that diurnal cortisol response may be associated with level of risk exposure in hazardous occupational subspecialties within policing compared with the general population.