jats:p One in five UK police officers suffers from Post-Traumatic Stress Disorder or Complex Post-Traumatic Stress Disorder, yet there is no gold standard measure of trauma exposure available. This study coded 4,987 exposures reported by 1,531 UK police officers, using their own language. The resulting checklist describes over 70% of typical ‘worst’ reported traumatic incidents (plus situational factors, including Covid19). The Police Traumatic Experiences Checklist is a practical tool of value for self-assessment and peer support, and can facilitate attempts by Occupational Health and management to improve monitoring and treatment access. </jats:p>