["Scandinavian Journal of Psychology, Volume 67, Issue 2, Page 596-604, April 2026. ", "\nABSTRACT\nFrontline police officers frequently face ambiguous and high‐pressure situations requiring rapid decision‐making under uncertainty. Traditional police training often emphasizes procedural and tactical skills, neglecting cognitive competencies such as situational awareness (SA) and shared mental models (SMM). This study investigates whether a brief, theoretically grounded decision‐making training program can enhance SA and team behavior among regular and SWAT‐type police officers during simulated arrest scenarios. A quasi‐experimental 2 × 2 factorial design was employed, involving 166 police officers (category 3: SWAT‐type; category 4: regular patrol). Participants were assigned to either a training group (n = 54) or a control group (n = 112). The training program consisted of three modules focusing on decision‐making frameworks, scenario‐based exercises, and group debriefings. SA was measured using the Situational Awareness Rating Scale (SARS), and team behavior was assessed by subject matter experts during ambiguous and non‐ambiguous simulated scenarios. Statistical analyses included factorial ANOVAs and planned comparisons. Trained officers demonstrated significantly higher SA scores than untrained controls (F(1, 162) = 12.587, p < 0.000). SWAT‐type officers outperformed regular officers in SA and team behavior across scenarios. A training effect on team behavior was observed only among regular officers in the ambiguous scenario (F(1, 81) = 6.66, p < 0.012). No training effect was found in the non‐ambiguous scenario. Effect sizes ranged from small to medium, with the strongest impact observed in SA and ambiguous decision‐making. Brief decision‐making training improved SA across both officer categories and enhanced team behavior in ambiguous scenarios for regular officers. These findings support the integration of scenario‐based, cognitively focused training in police education to better prepare officers for complex operational environments.\n"]