Journal of Forensic Biomechanics

Abstrait

Startle Response and Firearm Draw Performance in Law Enforcement Officers during a Lethal Force Simulated Domestic Assault

Michael A Kantor, Dane E. Bartz, William J. Lewinski, Robert W. Pettitt

In situations where Law Enforcement Officers (LEOs) must deploy their weapon, their ability to react and respond quickly is crucial. Prior research suggested that the controlled and predictable environments for training LEOs alter performance during a dynamic scenario. The present study evaluated the Startle Response (SR) and Firearm Draw Performance (FDP) of LEOs in response to a simulated unanticipated threat of lethal force with a firearm during a simulated domestic assault call. Twenty-two active duty LEOs (Age=34 ± 7 years; Body Mass=92 ± 12 kg; Height=181 ± 9 cm) engaged in a training scenario of a home visit as a follow up to a domestic violence call. An experimental trial resulted in a firearm ambush from distance of 6 m in the simulated home. LEOs were video-recorded and joint kinematics was measured using wearable sensors. A control trial was performed under no duress that was measured to provide a comparison of FDP. The average SR time was 0.78 s ± 0.44 s; the most common SR was neck flexion. FDP between conditions was significantly different (z=2.87, p<0.01) with the experimental trial 0.35 s ± 0.50 s slower. Initiation of the firearm draw occurred -0.19 s ± 0.51 s before the complete execution of the SR movement. Consistent exposure to dynamic training scenarios may improve FDP during lethal threats. The SR was observed in majority of LEOs following an unanticipated lethal threat stimulus therefore delaying the response to a threat and requiring a reframing of traditional reaction response paradigms.